Can you find the area of the Green shaded region? | Two Squares | (Olympiad Math) |

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  • Опубліковано 7 січ 2025

КОМЕНТАРІ • 51

  • @bigm383
    @bigm383 Рік тому +3

    Thanks, Professor, for some weekend fun!❤😀🥂

    • @PreMath
      @PreMath  Рік тому +1

      You are so welcome! ❤️🌹
      Thanks for your feedback! Cheers! 😀
      You are awesome. Keep it up 👍

  • @ganymed1236
    @ganymed1236 Рік тому +3

    What a good feeling on Sunday, I solved it by myself.😊
    Maths is one of my passions while retirement since this year. Please feed us! Thanks Sir and greetings from old Germany.🙋🏼

  • @francismoles9852
    @francismoles9852 Рік тому +5

    for calculating the area of BEP we also can use rapport of lenghts, for the area we can use the square of the rapport, for the triangle, the hypothenuse has a rapport of 1/5, for calculating the area of BEP we can calculate the area of CFP and multiply by 1/5 of square which is equal of 1/25, it gives 6 cm square

    • @PreMath
      @PreMath  Рік тому

      Thanks for your feedback! Cheers! 😀
      You are awesome. Keep it up 👍

  • @michaelsanders2655
    @michaelsanders2655 14 днів тому

    You’ll find that the triangle on the right side is a 3,4,5 triangle. Dimensions are 15,20,25.
    The empty small triangle at the top is also a 3,4,5 triangle…dimensions 3,4,5.
    The sides of the large square are 28, making the total area 784.
    784 - 250 - (area of small 3,4,5) =
    784 - 250 - 6 =528

  • @Ibrahimfamilyvlog2097l
    @Ibrahimfamilyvlog2097l Рік тому +3

    Good job 👌👍🌹

    • @PreMath
      @PreMath  Рік тому

      Thanks for your feedback! Cheers! 😀
      You are awesome. Keep it up 👍

  • @cyruschang1904
    @cyruschang1904 Рік тому

    each side of the small square = ✓(250 cm^2 + 150 cm^2) = 20 cm
    the three sides of the blue triangle => 20 cm, 150x2 cm^2/20 cm = 15 cm, ✓((20^2 + 15^2) cm^2) = ✓(625 cm^2) = 25 cm
    the hypotenuse of the white right-angled triangle = (250 cm^2 - 150 cm^2) / 20 cm = 5 cm
    the white triangle and the blue triangle are similar
    the remaining two sides of the white right-angled triangle: 5 cm (20/25) = 4 cm and 5 cm (15/25) = 3 cm
    each side of the large square = the hypotenuse of the blue triangle + the short side of the white triangle = 25 cm + 3 cm = 28 cm
    area of the white triangle = (4 cm)(3 cm)/2 = 6 cm^2
    green area = 28x28 cm^2 - 250 cm^2 - 6 cm^2 = 784 cm^2 - 256 cm^2 = 528 cm^2

  • @mathbynisharsir5586
    @mathbynisharsir5586 Рік тому +1

    Very Very useful video sir

    • @PreMath
      @PreMath  Рік тому

      Thanks dear ❤️

  • @masudi67
    @masudi67 Рік тому

    thanks Professor.....

  • @marioalb9726
    @marioalb9726 Рік тому +1

    Area of minor square
    A₁= 250+150=400 cm²
    Side of minor square:
    s = √A₁ = 20 cm
    Height of blue right triangle
    h = 2A/b = 150/20 = 15 cm
    Angle of rotation:
    tan α = 15/20
    α = 36,8699°
    Diagonal of minor square:
    d = √(2A₁) = 20√2 cm
    Side of mayor square:
    S = d cos (45°-α)
    S = 28 cm
    Green shaded area =
    Area of trapezoid - Area of isosceles right triangle
    A = A₂ - ½A₁
    A = ½(b+b)h - ½A₁
    A = ½[S+S-d.sin(45°-α)].S - ½A₁
    A= ½(2.28-4).28 - 400/2
    A = 728 - 200
    A = 528 cm² ( Solved √ )

  • @MrPaulc222
    @MrPaulc222 Рік тому +1

    Pretty much the same way here: I called the blue triangle a congruent 5x magnification of the white triangle making white a 3-4-5, so large square has sides of 28cm. I actually did this complete one in my head - no calculator, no pen and paper. 28^2 - 250 - 6.

    • @timeonly1401
      @timeonly1401 Рік тому +1

      The little white triangle is a 1/5-scale of the blue triangle' so the white triangle has area (1/5)^2 = 1/25th that of the blue triangle, or area of 6.

    • @MrPaulc222
      @MrPaulc222 Рік тому

      @@timeonly1401 Sure thing: 3-4-5 gives an area of 6 as does 150/25.

    • @PreMath
      @PreMath  Рік тому

      Excellent!
      Thanks for sharing! Cheers!
      You are awesome. Keep it up 👍

  • @3LLT33
    @3LLT33 Рік тому +2

    We don’t need to figure out EB because we know it’s a 3-4-5 right angle triangle.

  • @quigonkenny
    @quigonkenny 9 місяців тому

    Square CFEG:
    A = s²
    (250+150) = s²
    s² = 400
    s = √400 = 20
    Trapezoid EGCP:
    A = h(a+b)/2
    250 = 20(EP+20)/2
    250 = 10EP + 200
    10EP = 50
    EP = 5
    Triangle ∆CFP:
    FP² + CF² = PC²
    15² + 20² = PC²
    PC² = 225 + 400 = 625
    PC = √625 = 25
    As ∆PBE and ∆CFP share angles at P and are right triangles, they are similar.
    Triangle ∆PBE:
    PB/EP = FP/PC
    PB/5 = 15/25
    PB = (5)3/5 = 3
    BE/PB = CF/FP
    BE/3 = 20/15
    BE = (3)4/3 = 4
    A = bh/2 = 4(3)/2 = 6
    The green area equals the area of DCBA minus EGCP (250) minus ∆PBE (6).
    A = (25+3)² - 250 - 6
    A = 784 - 256 = 528 cm²

  • @michaelgarrow3239
    @michaelgarrow3239 Рік тому +2

    I converted cm to parsecs- it was a so much bigger problem to solve.

  • @juergenilse3259
    @juergenilse3259 Рік тому +1

    The area of the small square is 250+150=400=20^2, so thhe side length of the small square is 20. the blue triangle has the area of 150 and one leg of length 20, so the other leg of this right triangle must have length 15. (because the area is 150). So the hypotenuse of thhis triangle mmust be 25 (pythagoras). The small white triangle is siilar to the green triangle and hypotenuse of 5, so the lengt of the legs are 4 and 5 and therefor the are is 4*3/2=6. The side length of the big sqare is 25+3=28, so the areaof the big square is 28^2=784. The green area is the area of the big square minus area of the white triangle minus 250, i.e 784-6-250=528.

    • @PreMath
      @PreMath  Рік тому +1

      Excellent!
      Thanks for sharing! Cheers!
      You are awesome. Keep it up 👍

    • @juergenilse3259
      @juergenilse3259 Рік тому

      @@PreMathThanks. i first mixed up the length of the sides of the blue triangle and calculated with 23^2 as the area of the big square, but i saw my mistake and corrected the error ...

  • @Copernicusfreud
    @Copernicusfreud Рік тому +1

    Yay! I solved the problem.

    • @PreMath
      @PreMath  Рік тому

      Super ❤️
      You are awesome. Keep it up 👍

  • @danieldennis9831
    @danieldennis9831 Рік тому

    ⇒A⬠AEGCD=528
    Given: A⏢GCPE=250, A△PFC=150, □GCFE and □ABCD are at different angles and overlap, with corners of □GCFE hitting sides of □ABCD at points E and P
    Use A□=s²: for □GCFE, A=250+150, A=400; s²=400 ∴for □GCFE, s=20 Line GE=20, GC=20, EF=20
    Set point J: Draw line ∥ FC, from point P. line intersects line GC at point J
    ⒸA△PFC=150, △PJC≅△PFC ∴△PJC∾△PFC, A△PJC=150
    A⏢GCPE=250, A△PJC=150 ∴▭GJPE=100
    Use A▭=bh; A▭GJPE=100 100=20•GJ; ∴line GJ=5
    ∴Line JC=15 (NB could have figured this earlier)
    Use a²+b²=c² WHERE △ABC is right triangle
    15²+20²=Line CP² 225+400=CP² 625=CP² ∴CP=25
    For ∠CPF, ∠CPF∾∠EPB Adj/Opp(COT)=3/4
    ∴line PE=5
    EB²+BP²=PE 3²+4²=5² ∴PB=3, A△EPB=6
    CP+PB=28, A□ABCD=28² ∴A□ABCD=784
    A⬠AEGCD=784-6-250
    ⇒A⬠AEGCD=528
    I was going to use letters and numbers with circles to point back to earlier conclusions but as I am only writing answer to ensure I leave a comment (algorithm purposes) I changed my mind.
    My list of symbols I now use for math proofs now include (copy as desired):
    ⇒√∛∜±≈∉∈≡•÷±≥≤≠≟≝¯⁰¹²³⁴⁵⁶⁷⁸⁹ˣᵐⁿᵃᵇ⁺⁻ᐟ⸍⁼⁽⁾≮≯≨≩≅≆≌≝∾∾∿≈≉≣≢≡|∥∢∡∠△□⏢▭▱⬠°⌠⋅¼⅓½⅔¾∞αβπδΩθ°⌠µ!∑∪∫∶∷∝∴∵∋①②③④⑤⑥⑦⑧⑨⑩ⒶⒷⒸⒹⒺⒻⒼ

  • @himo3485
    @himo3485 Рік тому +1

    250+150=400=20²
    20*PF/2=150 PF=15 EP=5
    PC=√[15²+20²]=25
    BP/5 = 15/25 BP=3
    BP+PC=3+25=28
    EB/3 = 20/15 EB=4
    EBP=3*4/2=6
    area of Green Region : 28*28 - (250+6) = 784 - 256 = 528cm²

    • @PreMath
      @PreMath  Рік тому

      Thanks for sharing! Cheers!
      You are awesome. Keep it up 👍

  • @timurkodzov718
    @timurkodzov718 Рік тому +2

    I solved the problem and I by my calculation it is also 528 cm².

    • @PreMath
      @PreMath  Рік тому +1

      Excellent!
      You are awesome. Keep it up 👍

  • @santiagoarosam430
    @santiagoarosam430 Рік тому +1

    FC=√(250+150) =20 → PF=2*150/20=15 → EP=20-15=5 →→ 5*3=15 y 5*4=20 → PC=5*5=25 →→ s= EP/PC =5/25=1/5 → BP=15s=15/5=3 → BC=3+25=28 →→ EBP=PFCs²=150*(1/25)=6 →→→ Área verde =28² - 250 - 6 =528
    Gracias y un saludo cordial.

    • @PreMath
      @PreMath  Рік тому

      Excellent! ❤️
      Thanks for sharing! Cheers!
      You are awesome. Keep it up 👍

  • @killing_gaming0973
    @killing_gaming0973 Рік тому

    We cannot like assume EFCG is a perfect square unless it is given

  • @giuseppemalaguti435
    @giuseppemalaguti435 Рік тому +1

    ....,L=28....Ah=28^2-250-4*3/2=784-250-6=528

    • @PreMath
      @PreMath  Рік тому

      Excellent! ❤️
      Thanks for sharing! Cheers!
      You are awesome. Keep it up 👍

  • @wackojacko3962
    @wackojacko3962 Рік тому +1

    😎

  • @abdulkadirbuyuksoy2076
    @abdulkadirbuyuksoy2076 Рік тому +1

    Easy

  • @prossvay8744
    @prossvay8744 Рік тому +1

    A=528

    • @PreMath
      @PreMath  Рік тому

      Excellent! ❤️
      Thanks for sharing! Cheers!
      You are awesome. Keep it up 👍

  • @trishanuagarwal9220
    @trishanuagarwal9220 Рік тому

    Sir i think you have an error in the Sol
    While us😢ratio of similar triangles
    It should be
    BP/5=20/25
    And then continue
    So ans would i guess
    29²-250-6=585cm²

    • @boneistt
      @boneistt Рік тому +4

      No, there’s no mistake; the ratio of the shortest side and hypotenuse of the small triangle (BP/EP) is the same as the ratio of the shortest side and hypotenuse of the big triangle (FP/CP). That is:
      BP/EP = BP/5 = FP/CP = 15/25 = 3/5
      You can tell this is correct by recognising that the big triangle is a 3,4,5 special triangle (15,20,25 -> 5*3,5*4,5*5), and as the big and little triangles are similar triangles, you know it’s also a 3,4,5 special triangle, and given the hypotenuse is 5, you know the other two sides must be 3 and 4.

    • @trishanuagarwal9220
      @trishanuagarwal9220 Рік тому

      @@boneistt thank you for pointing it out bro

  • @DB-lg5sq
    @DB-lg5sq Рік тому

    528

  • @warren-j9x
    @warren-j9x Рік тому

    THE AREA OF THE BLUE TRIANGLE IS IRELEVANT

    • @quigonkenny
      @quigonkenny 9 місяців тому

      Don't see how you can get the area of the angled square without it. You could rotate the angled square clockwise or counterclockwise and keep the overlap area at 250cm² and it would change both the area of the angled square and the larger square, not to mention the green area. There's nothing which sets what percentage of the angled square overlaps other than the differences in the areas. You can certainly determine all the dimensions of the problem from the yellow trapezoid alone (even the blue triangle, by dropping a perpendicular to GC from P), but not without knowing the full area of the angled square or at least it's side length, which you can't get from the trapezoid alone. Given just the yellow area alone, since the diagram is not necessarily to scale, the angled square side length could be anywhere from 16 to 22, and that's just the integer values (it's actually between 5√10 and 10√5).