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Can you find area of the Yellow shaded Square? | (Triangle) |

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  • Опубликовано: 13 авг 2024
  • Learn how to find the area of the Yellow shaded Square inscribed in the right Triangle. Important Geometry and Algebra skills are also explained: similar Triangles; Pythagorean Theorem. Step-by-step tutorial by PreMath.com
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Комментарии • 96

  • @himo3485
    @himo3485 Месяц назад +11

    7 : 14 = 1 : 2 ED=DF=x FC=2x
    x²+(2x)²=14² 5x²=196
    Yellow Area = x*x = x² = 196/5 = 39.2

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

    • @erdemakca433
      @erdemakca433 Месяц назад

      I solve at the same way. I found the same.

  • @hongningsuen1348
    @hongningsuen1348 Месяц назад +2

    Method using similar triangles and Pythagoras theorem:
    1. Let side of yellow square be 2a.
    2. Triangles ADE and DCF are similar, by corresponding sides proportionality equations,
    AE = a, CF = 4a
    3. Hence AB = 3a and BC = 6a
    4. In triangle ABC, by Pythagoras theorem, (7+14)^2 = (3a)^2 + (6a)^2
    Hence a^2 = 49/5
    5. Area of yellow square = (2a)^2 = 4a^2 = 196/5

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @eduardozappi6397
    @eduardozappi6397 Месяц назад +12

    sin²β + cos²β = 1 ------ sin(β) = a/14 ----- cos(β) = a/7 ---- (a²/196) + (a²/49) = 1 ---- a² = 39.2 ----- yellow area = 39.2 square units
    I love your channel

    • @PreMath
      @PreMath  Месяц назад +1

      Excellent! You are the best!
      Glad to hear that!
      You are very welcome!
      Thanks for sharing ❤️

    • @davidseed2939
      @davidseed2939 Месяц назад +1

      θ=smaller angle
      s=sinθ, c=cosθ
      consider sides of the square
      14s=7c
      2s=c
      4ss=cc=1-ss
      ss=1/5
      Area =(14s)²= 196/5=39.2

  • @unknownidentity2846
    @unknownidentity2846 Месяц назад +2

    Let's find the area:
    .
    ..
    ...
    ....
    .....
    The right triangles ADE and CDF are obviously similar. So with s being the side length of the square we can conclude:
    AE/DF = DE/CF = AD/CD
    AE/s = s/CF = 7/14 = 1/2
    AE/s = 1/2 ⇒ AE = s/2 ⇒ AB = AE + BE = s/2 + s = 3*s/2
    s/CF = 1/2 ⇒ CF = 2*s ⇒ BC = BF + CF = s + 2*s = 3*s
    The triangle ABC is also a right triangle. Therefore we can apply the Pythagorean theorem in order to obtain the area of the yellow square:
    AB² + BC² = AC²
    AB² + BC² = (AD + CD)²
    (3*s/2)² + (3*s)² = (7 + 14)²
    9*s²/4 + 9*s² = 21² = 3²*7²
    s²/4 + s² = 7²
    (5/4)*s² = 49
    ⇒ A(BEDF) = s² = 4*49/5 = 196/5 = 39.2
    Best regards from Germany

    • @PreMath
      @PreMath  Месяц назад +1

      Excellent! You are the best!👍
      Thanks for sharing ❤️

  • @quigonkenny
    @quigonkenny Месяц назад +5

    Fairly simple. Answer I came up with in my head: 196/5 sq units
    Now let's see if I'm right:
    Let s be the side length of square BEDF, so BE = ED = DF = FB = s. Let ∠BAC = α and ∠ACB = β, where α and β are complementary angles that sum to 90°. As ∠DEA = 90°, ∠ADE = 90°- α = β, and as ∠EDF = 90°, ∠FDC = 180°-90°- β = α, so ∆DEA and ∆CFD are similar to ∆ABC and to each other.
    BA/FD = AC/DC
    BA/s = 21/14 = 3/2
    BA = 3s/2
    CB/DE = AC/AD
    CB/s = 21/7 = 3
    CB = 3s
    BA² + CB² = AC²
    (3s/2)² + (3s)² = 21²
    9s²/4 + 9s² = 441
    45s²/4 = 441
    s² = 441(4/45) = 49(4/5) = 196/5 = 39.2 sq units

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @santiagoarosam430
    @santiagoarosam430 Месяц назад +5

    Los triángulos AED y DFC son semejantes→ Razón de semejanza s=7/14=1/2→ Si ED=b→AE=b/2→ b²+(b/2)²=7²→ b²=4*49/5=196/5=39,20 ud².
    Gracias y un saludo cordial.

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @Alishbafamilyvlogs-bm4ip
    @Alishbafamilyvlogs-bm4ip Месяц назад +2

    Very beautiful video nice information thanks for sharing❤

    • @PreMath
      @PreMath  Месяц назад

      So nice of you
      Thanks for the feedback ❤️

  • @devondevon4366
    @devondevon4366 Месяц назад +2

    39.2
    The triangles are similar
    Let the side of the square = n
    Let the base of the the triangle on the right = p, then
    n/7 = p/14
    14n= 7p
    2n = p
    Therefore, the longest base of each triangle is TWICE the shortest base.
    Therefore, the length of the base of the big triangle = 3n (2n + n)
    Hence, the shortest base for the triangle on top is 0.5n. Hence, the length of the base of the big triangle = 1.5n (n + 0.5n)
    Hence, the sides of the big triangle are 1.5n , 3n and 21 (14+ 7)
    Let's employed Pythagorean Theorem
    (1.5n)^2 + (3n)^2 = 21^2
    2.25n ^2 + 9n^2 = 441
    11.25n^2 = 441
    n^2= 39.2

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @marcelowanderleycorreia8876
    @marcelowanderleycorreia8876 Месяц назад +2

    Very good aproach!!

    • @PreMath
      @PreMath  Месяц назад

      Glad to hear that!
      Thanks for the feedback ❤️

  • @RAG981
    @RAG981 Месяц назад +2

    Intercept theorem says FC/14=a/7, so FC= 2a, then finish as you did.

    • @PreMath
      @PreMath  Месяц назад +1

      Thanks for the feedback ❤️

  • @georgebliss964
    @georgebliss964 Месяц назад +1

    Angle ADE = angle DCF.
    Cos DCF (ADE) = a / 7.
    Sin DCF = a /14.
    Tan = Sin / Cos.
    Tan DCF = (a / 14) / (a / 7)
    Tan DCF = (a /14) x (7 / a)
    Tan DCF = 1/2 = 0.5.
    Tan -1, DCF = 26.565 degrees.
    Sin 26.565 = a / 14.
    a = 14 sin 26.565 = 6.261.
    Area= 6.261^2 = 39.2.

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @phungpham1725
    @phungpham1725 Месяц назад +1

    Let a be the side of the square.
    The two triangles AED and ABC are similar--> ED/BC=AD/AC=7/21=1/3-a/BC=1/3--> BC=3a -->FC=2a
    Consider the triangle DFC
    Sqa+Sq (2a)=sq14
    Sqa=sq14/5
    Area of the yellow square=196/5=39.2 sq units😊

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @user-sk9oi9jl2g
    @user-sk9oi9jl2g Месяц назад +3

    Три подобных треугольника. Немного по другому решала. Но тоже через подобие.

    • @PreMath
      @PreMath  Месяц назад +1

      Супер! Спасибо

  • @preetjitsingh328
    @preetjitsingh328 Месяц назад

    Taking the secant of the shared triange of the smallest triangle and the biggest one as the same. Let length of 🟨 = a
    7/ ( 49-a^2)^.5 = 21/ (a+(49-a^2)^.5
    Divide by 7 and cross miltiply
    A + (49- a^2)^.5 = 3(49-a^2)^0.5
    Remove the extra (49-a^2)^0.5
    A = 2 (49- a^2) ^ 0.5
    Square both sides
    A^2 = 4 ( 49- a^2)
    A^2 on one side
    5a^2= 196
    A^2= 196/5#

  • @marcgriselhubert3915
    @marcgriselhubert3915 Месяц назад +1

    Triangles AED and DFC are similar, FC/ED = 14/4 = 2,
    so FC = 2.c with c the side length of the square.
    Then in triangle DFC DC^2 = DF^2 + FC^2,
    or 14^2 = 4.c^2 + c^2. So c^2 = 14^2/5
    The area of the square is c^2 = 14^2/5 = 196/5.

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @himadrikhanra7463
    @himadrikhanra7463 Месяц назад

    No .1 similarity
    2. Summation of area of triangles and square by assuming sides x,y and a little bit manipulation of sides length..
    3. Formula: ab / a + b = x. Delta ( abc) = x^2!

    • @PreMath
      @PreMath  Месяц назад

      Thanks for the feedback ❤️

  • @yalchingedikgedik8007
    @yalchingedikgedik8007 Месяц назад +1

    Thanks Sir
    Thanks PreMath
    Very nice and useful
    We are learning more about Math.
    Good luck with glades
    ❤❤❤❤

    • @PreMath
      @PreMath  Месяц назад

      So nice of you, dear
      You are very welcome!
      Thanks for the feedback ❤️

  • @jamestalbott4499
    @jamestalbott4499 Месяц назад +2

    Thank you!

    • @PreMath
      @PreMath  Месяц назад

      You are very welcome!
      Thanks for the feedback ❤️

  • @tijanimaths6006
    @tijanimaths6006 Месяц назад +3

    👍👍👍

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for the feedback ❤️

  • @stevetitcombe939
    @stevetitcombe939 Месяц назад +1

    Because the triangles CDF and DEA are similar with a length scaling of 2 then we can see that the smaller right angle triangle DEA comprises a hypotenues of length 7 and base side and height side lengths of lengths "a" and "1/2a" respectively.
    Using pythag we see that 7^2=a^2 + (1/2a)^2.
    Expanding out we see that
    49 = a^2 + 1/4 a^2 = 5/4 a^2
    Rearranging we see that
    a^2 (which also happens to be the area of yellow square = (4 . 49)/5 =39.2 units^2
    Simple

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @PrithwirajSen-nj6qq
    @PrithwirajSen-nj6qq Месяц назад +1

    🔺 ABC
    BC Ii ED
    Hence
    AE/EB=7/14=1/2
    AE/ED=1/2 (as EB =ED)
    ED=2 AE
    🔺 AED
    AE^2 +ED^2=49
    AE^2+(2AE^2)=49
    AE=7/√5
    2AE=14/√5
    Area =(14/√5)^2=196/5 sq units
    Comment please

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @sergeyvinns931
    @sergeyvinns931 Месяц назад +1

    (b-x)/7=x/14, b=3x/2, (a-x)/14=x/7, a=3x, a^2+b^2=21^2, (3x)^2+(3x/2)^2=441, 45x^2/4=441, x^2=441*4/45, x^2=39,2.
    Area of the shaded Square = 39,2.

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @cyruschang1904
    @cyruschang1904 Месяц назад

    The 📐 above the ⬛ and the 📐 to the right of the ⬛ are similar
    If each side of the ⬛ is x
    The 3 sides of the small 📐 are x/2, x, 7
    The 3 sides of the large 📐 are x, 2x, 14
    x^2 + 4x^2 = 14^2
    area of the square = x^2 = (14^2)/5 = 196/5 = 39 + 1/5

  • @rabotaakk-nw9nm
    @rabotaakk-nw9nm Месяц назад

    3:33-6:33 ΔAED ~ ΔDFC (AA) =>
    => ED/AD=FC/DC => FC=a•14/7=2a

  • @iveswidmer1027
    @iveswidmer1027 Месяц назад

    As the big and the small triangle are similar and 7 is the half of 14, AE is half DF.
    So (1/2a)^2+a^2=7^2 => 1.25.a^2=49 =>a^2=39.2

  • @wackojacko3962
    @wackojacko3962 Месяц назад +1

    @ 6:59 , I absolutely love filling in the blanks of the Pagan Formula a² + b² = c². Life is good. 🙂

    • @PreMath
      @PreMath  Месяц назад +1

      👍😀
      Excellent!
      Thanks for the feedback ❤️

  • @AmirgabYT2185
    @AmirgabYT2185 Месяц назад +3

    S=39,2 square units

    • @PreMath
      @PreMath  Месяц назад +1

      Excellent!
      Thanks for sharing ❤️

  • @juergenilse3259
    @juergenilse3259 Месяц назад +1

    Let x the side length of the square. The triangle right of the square and the triangle topof the square are similar..The hypothenuse of the triangle top of the squareis hallf the lengthof zje hpothhenuse of the square right of the square. So the length of the legs of the triangle right of the square are x and 2x. Accordng to pythagoras, we have the equation
    x^2+(2x)^2=14^2
    x^2+4x^2=196
    5x^2=196
    x^2=39,2
    That is also the area of the square.
    It is unnecessary to calculate the length of BC,because we can get the length of FC directly from the similarity of the 2 triangles rigthof the square and top of the square.

    • @PreMath
      @PreMath  Месяц назад +1

      Excellent!
      Thanks for sharing ❤️

  • @MrPaulc222
    @MrPaulc222 Месяц назад +1

    If the square's sides are x, then FC = 2x due to the 7:14 ratio.
    By the same principle, AB is one and a half x so (3/2)x, making AE ((1/2)x
    Although the triangles are similar, it looks like I need an additional parameter from somewhere.
    The base is twice the height.
    tan(-1)(1/2) is 26.57deg so want ED/7 = cos(26.57)
    7*cos(26.57) = 6.26...
    Square it for 39.19 un^2 (rounded)
    I have now looked. Your way was cleaner, not least because it gave an exact answer rather than relying on the close approximations of trigonometry.
    Thank you.

    • @PreMath
      @PreMath  Месяц назад

      👍😀
      You are very welcome!
      Thanks for the feedback ❤️

  • @user-sp2bw2dq5d
    @user-sp2bw2dq5d Месяц назад

    a/14 = sinα
    a/7 = cosα
    tgα = sinα/cosα = (a/14)/(a/7) = 1/2
    b = AE = a*tgα = a/2
    a² + b² = 7²
    a² + a²/4 = 49
    5a²/4 = 49
    a² = 4*49/5 = 39.2
    Keep It Simple

  • @brettgbarnes
    @brettgbarnes Месяц назад +1

    CF/ED = 14/7
    CF= 2ED
    DF = ED
    CF² + DF² = 14²
    (2ED)² + ED² = 14²
    (2a)² + a² = 14²
    4a² + a² = 196
    5a² = 196
    a² = 196/5

  • @MrPaulc222
    @MrPaulc222 Месяц назад +1

    I missed a trick here. With x as the square's side length, I could have gone for (3x)^2 + ((3/2)x)^2 = 21^2
    9x^2 + (9/4)x^2 = 441
    (45/4)x^2 = 441, ---> 45x^2 = 1764 ---> x^2 = 1764/45 = 39.2

    • @PreMath
      @PreMath  Месяц назад

      Well done!
      Thanks for sharing ❤️

  • @LuisdeBritoCamacho
    @LuisdeBritoCamacho Месяц назад +1

    STEP-BY-STEP RESOLUTION PROPOSAL :
    01) BE = BF = FD = ED = X
    02) FC = Y
    03) 7 / X = 14 / Y
    04) As : DC = 14 and AD = 7, 14 = (2 * 7); one can easily see that FC = 2X, and AE = X / 2
    05) X^2 + (2X)^2 = 196 ; 5X^2 = 196 ; X^2 = 196 / 5 ; X^2 = 39,2
    06) (X/2)^2 + X^2 = 49 ; X^2 / 4 + X^2 = 49 ; X^2 + ^2 = (49 * 4) ; 5X^2 = 196 ; X^2 = 196 / 5 ; X^2 = 39,2
    07) It seems to me that the Yellow Area is Equal to 39,2 Square Units.
    Best Regards from the Department of Ancient (Indo-Arabic and Persian) Mathematical Thinking, Knowledge, and Wisdom. AL ANDALUS DISTRICT.

    • @PreMath
      @PreMath  Месяц назад +1

      Amazing!👍
      Thanks for sharing ❤️

  • @td7302
    @td7302 Месяц назад

    (L' Aire ) /Le petit carré = 30,8 .le petit triangle = 11,76. Le grand triangle = 47,05 M² . Sur la base 3 , 4, 5 .

    • @PreMath
      @PreMath  Месяц назад

      Thanks for the feedback ❤️

  • @user-lo7hg8zy4x
    @user-lo7hg8zy4x Месяц назад

    Let's make it quicker
    Sin(Thida) = X/14 = sqrt(49-X^2)/7
    7X = 14 sqrt(49-X^2)
    X = 2.sqrt(49-X^2)
    X^2 = 4(49-X^2)
    X^2 =196-4X^2
    5X^2 =196
    X^2 = 39.2

  • @Tom-zu2yc
    @Tom-zu2yc Месяц назад

    The video ephasizes how many different paths you can dive into looking for your solution. Always something to learn from.
    However, reading the comments from so many viewers it is hard not to get the impression that the video is missing the obvoius ratio 7:14 staring at you even before you start the video. And that ratio makes the problem so easy, that most viewers find the solution in their heads.
    Maybe next time it would make sense to change the angles a little, so finding the ratio actually requires a pen and paper for most.
    Anyway, great work!

  • @tlmotorscbb
    @tlmotorscbb Месяц назад

    Triangle AED is similar to DCF, so all their sides are proportional. DC is twice AD so FC is 2a.

  • @user-sw9lb2zs6e
    @user-sw9lb2zs6e Месяц назад

    Let AE be x. (a+x):a=21:14=3:2. Hence 1/2a^2+a^2=49. Finished! a^2=39,2

  • @HamedAhmadi-tj6vf
    @HamedAhmadi-tj6vf 19 дней назад

    Solving 21/(a+sqrt(7^2 - a^2))=14/a for a
    a = 39.2E^2
    I used geometry

  • @giuseppemalaguti435
    @giuseppemalaguti435 Месяц назад +1

    arccos(l/7)=arcsin(l/14)...√(1-l^2/49)=l/14...l^2=196/5

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @JSSTyger
    @JSSTyger Месяц назад +2

    196/5

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for sharing ❤️

  • @m0csk0s_lopitikus
    @m0csk0s_lopitikus 20 дней назад

    14²/5=39.2

  • @misterenter-iz7rz
    @misterenter-iz7rz Месяц назад +1

    Interesting but easy puzzle, (3s)^2+(3/2 s)^2=45/4 s^2=21^2, s^2=4×21^2/45=4×49/5=4×49×5/25, s=14/5 sqrt(5), bit the answer is simply 39.2.

    • @PreMath
      @PreMath  Месяц назад

      Excellent!
      Thanks for the feedback ❤️

  • @sutediheriyonoBaladMaUng
    @sutediheriyonoBaladMaUng 18 дней назад

    36 dim²

  • @lk-wr2yn
    @lk-wr2yn Месяц назад

    49/1,25 (1,25=1^2+0,5^2)

    • @PreMath
      @PreMath  Месяц назад +1

      Thanks for sharing ❤️

  • @ahmedaboutir7026
    @ahmedaboutir7026 Месяц назад

    245

  • @ilianstoychev1660
    @ilianstoychev1660 20 дней назад

    AD=DF, so 7*7=49, chearS

  • @grantsutherland6798
    @grantsutherland6798 Месяц назад

    I'll do it in CAD, much easier

    • @PreMath
      @PreMath  Месяц назад +1

      Thanks for the feedback ❤️

  • @himadrikhanra7463
    @himadrikhanra7463 27 дней назад

    196 ?

  • @user-lt7me8sj1m
    @user-lt7me8sj1m Месяц назад

    Самый простой способ.

  • @kranik1
    @kranik1 Месяц назад +1

    Какой же нудный этот индус!

  • @hgdanielkim2671
    @hgdanielkim2671 Месяц назад

    여기저기 정치판검사들이 판치는 군요