Find the area of the shaded region in the figure below:

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











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Find the area of the shaded region in the figure below:



enter image description here



I am completely stuck on how to start off this question. Please help on some guidance on how to start it off.










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  • Unless I am very mistaken, Mind Your Decisions made a video on this exact problem.
    – Raptor
    5 hours ago










  • @Raptor, I've checked his YouTube channel, you're right thanks. An alternative approach will also be appreciated.
    – Meghan C
    5 hours ago











  • Hint: the sum of areas of two quadrilaterals on upper-left and lower-right equal to the sum of areas of the two quadrilaterals on upper-right and lower-left.
    – achille hui
    5 hours ago






  • 2




    @achillehui, thanks, I will attempt that approach. May I ask why this is true?
    – Meghan C
    5 hours ago















up vote
3
down vote

favorite
2












Find the area of the shaded region in the figure below:



enter image description here



I am completely stuck on how to start off this question. Please help on some guidance on how to start it off.










share|cite|improve this question





















  • Unless I am very mistaken, Mind Your Decisions made a video on this exact problem.
    – Raptor
    5 hours ago










  • @Raptor, I've checked his YouTube channel, you're right thanks. An alternative approach will also be appreciated.
    – Meghan C
    5 hours ago











  • Hint: the sum of areas of two quadrilaterals on upper-left and lower-right equal to the sum of areas of the two quadrilaterals on upper-right and lower-left.
    – achille hui
    5 hours ago






  • 2




    @achillehui, thanks, I will attempt that approach. May I ask why this is true?
    – Meghan C
    5 hours ago













up vote
3
down vote

favorite
2









up vote
3
down vote

favorite
2






2





Find the area of the shaded region in the figure below:



enter image description here



I am completely stuck on how to start off this question. Please help on some guidance on how to start it off.










share|cite|improve this question













Find the area of the shaded region in the figure below:



enter image description here



I am completely stuck on how to start off this question. Please help on some guidance on how to start it off.







geometry area






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share|cite|improve this question




share|cite|improve this question










asked 5 hours ago









Meghan C

19227




19227











  • Unless I am very mistaken, Mind Your Decisions made a video on this exact problem.
    – Raptor
    5 hours ago










  • @Raptor, I've checked his YouTube channel, you're right thanks. An alternative approach will also be appreciated.
    – Meghan C
    5 hours ago











  • Hint: the sum of areas of two quadrilaterals on upper-left and lower-right equal to the sum of areas of the two quadrilaterals on upper-right and lower-left.
    – achille hui
    5 hours ago






  • 2




    @achillehui, thanks, I will attempt that approach. May I ask why this is true?
    – Meghan C
    5 hours ago

















  • Unless I am very mistaken, Mind Your Decisions made a video on this exact problem.
    – Raptor
    5 hours ago










  • @Raptor, I've checked his YouTube channel, you're right thanks. An alternative approach will also be appreciated.
    – Meghan C
    5 hours ago











  • Hint: the sum of areas of two quadrilaterals on upper-left and lower-right equal to the sum of areas of the two quadrilaterals on upper-right and lower-left.
    – achille hui
    5 hours ago






  • 2




    @achillehui, thanks, I will attempt that approach. May I ask why this is true?
    – Meghan C
    5 hours ago
















Unless I am very mistaken, Mind Your Decisions made a video on this exact problem.
– Raptor
5 hours ago




Unless I am very mistaken, Mind Your Decisions made a video on this exact problem.
– Raptor
5 hours ago












@Raptor, I've checked his YouTube channel, you're right thanks. An alternative approach will also be appreciated.
– Meghan C
5 hours ago





@Raptor, I've checked his YouTube channel, you're right thanks. An alternative approach will also be appreciated.
– Meghan C
5 hours ago













Hint: the sum of areas of two quadrilaterals on upper-left and lower-right equal to the sum of areas of the two quadrilaterals on upper-right and lower-left.
– achille hui
5 hours ago




Hint: the sum of areas of two quadrilaterals on upper-left and lower-right equal to the sum of areas of the two quadrilaterals on upper-right and lower-left.
– achille hui
5 hours ago




2




2




@achillehui, thanks, I will attempt that approach. May I ask why this is true?
– Meghan C
5 hours ago





@achillehui, thanks, I will attempt that approach. May I ask why this is true?
– Meghan C
5 hours ago











2 Answers
2






active

oldest

votes

















up vote
3
down vote



accepted










A square into 4 areas



Split the square into $8$ triangles, convince yourself you can group them into 4 pairs
and each pair has same area. Let the area of the triangles be $a, b, c, d$ as illustrated above.



You are given $c + d = 20$, $b + c = 32$ and $a + d = 16$. The area of the quadrilateral (in cyan) is
$$a + b = (a + d) + ( b + c) - ( c + d) = 16 + 32 -20 = 28$$






share|cite|improve this answer




















  • +1 Nice Answer!!
    – the_candyman
    4 hours ago










  • @achillehui, I really appreciate your help. Thank you.
    – Meghan C
    4 hours ago

















up vote
1
down vote













Alternatively, refer to the figure:



$hspace4cm$![enter image description here



Let $x$ be the half of the side of the large square. Then the side of the smaller oblique square is $xsqrt2$, how:




Pythagorean theorem.




The total green area is $x^2$, how:




$$frac12 cdot xsqrt2cdot h_1+frac12 cdot xsqrt2 cdot h_2=frac12cdot xsqrt2cdot (h_1+h_2)=frac12cdot xsqrt2cdot xsqrt2=x^2.$$




The total area of grey and green regions is $2x^2=16+32=48$, how:




Green area is $x^2$ and grey area is $2cdot fracx^22=x^2$.




Hence, the required area is $96-(16+20+32)=28$, how:




the area of the large square $(4x^2)$ minus the total area of grey, green and white regions $16+20+32$.







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    2 Answers
    2






    active

    oldest

    votes








    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    3
    down vote



    accepted










    A square into 4 areas



    Split the square into $8$ triangles, convince yourself you can group them into 4 pairs
    and each pair has same area. Let the area of the triangles be $a, b, c, d$ as illustrated above.



    You are given $c + d = 20$, $b + c = 32$ and $a + d = 16$. The area of the quadrilateral (in cyan) is
    $$a + b = (a + d) + ( b + c) - ( c + d) = 16 + 32 -20 = 28$$






    share|cite|improve this answer




















    • +1 Nice Answer!!
      – the_candyman
      4 hours ago










    • @achillehui, I really appreciate your help. Thank you.
      – Meghan C
      4 hours ago














    up vote
    3
    down vote



    accepted










    A square into 4 areas



    Split the square into $8$ triangles, convince yourself you can group them into 4 pairs
    and each pair has same area. Let the area of the triangles be $a, b, c, d$ as illustrated above.



    You are given $c + d = 20$, $b + c = 32$ and $a + d = 16$. The area of the quadrilateral (in cyan) is
    $$a + b = (a + d) + ( b + c) - ( c + d) = 16 + 32 -20 = 28$$






    share|cite|improve this answer




















    • +1 Nice Answer!!
      – the_candyman
      4 hours ago










    • @achillehui, I really appreciate your help. Thank you.
      – Meghan C
      4 hours ago












    up vote
    3
    down vote



    accepted







    up vote
    3
    down vote



    accepted






    A square into 4 areas



    Split the square into $8$ triangles, convince yourself you can group them into 4 pairs
    and each pair has same area. Let the area of the triangles be $a, b, c, d$ as illustrated above.



    You are given $c + d = 20$, $b + c = 32$ and $a + d = 16$. The area of the quadrilateral (in cyan) is
    $$a + b = (a + d) + ( b + c) - ( c + d) = 16 + 32 -20 = 28$$






    share|cite|improve this answer












    A square into 4 areas



    Split the square into $8$ triangles, convince yourself you can group them into 4 pairs
    and each pair has same area. Let the area of the triangles be $a, b, c, d$ as illustrated above.



    You are given $c + d = 20$, $b + c = 32$ and $a + d = 16$. The area of the quadrilateral (in cyan) is
    $$a + b = (a + d) + ( b + c) - ( c + d) = 16 + 32 -20 = 28$$







    share|cite|improve this answer












    share|cite|improve this answer



    share|cite|improve this answer










    answered 4 hours ago









    achille hui

    91.6k5127248




    91.6k5127248











    • +1 Nice Answer!!
      – the_candyman
      4 hours ago










    • @achillehui, I really appreciate your help. Thank you.
      – Meghan C
      4 hours ago
















    • +1 Nice Answer!!
      – the_candyman
      4 hours ago










    • @achillehui, I really appreciate your help. Thank you.
      – Meghan C
      4 hours ago















    +1 Nice Answer!!
    – the_candyman
    4 hours ago




    +1 Nice Answer!!
    – the_candyman
    4 hours ago












    @achillehui, I really appreciate your help. Thank you.
    – Meghan C
    4 hours ago




    @achillehui, I really appreciate your help. Thank you.
    – Meghan C
    4 hours ago










    up vote
    1
    down vote













    Alternatively, refer to the figure:



    $hspace4cm$![enter image description here



    Let $x$ be the half of the side of the large square. Then the side of the smaller oblique square is $xsqrt2$, how:




    Pythagorean theorem.




    The total green area is $x^2$, how:




    $$frac12 cdot xsqrt2cdot h_1+frac12 cdot xsqrt2 cdot h_2=frac12cdot xsqrt2cdot (h_1+h_2)=frac12cdot xsqrt2cdot xsqrt2=x^2.$$




    The total area of grey and green regions is $2x^2=16+32=48$, how:




    Green area is $x^2$ and grey area is $2cdot fracx^22=x^2$.




    Hence, the required area is $96-(16+20+32)=28$, how:




    the area of the large square $(4x^2)$ minus the total area of grey, green and white regions $16+20+32$.







    share|cite|improve this answer
























      up vote
      1
      down vote













      Alternatively, refer to the figure:



      $hspace4cm$![enter image description here



      Let $x$ be the half of the side of the large square. Then the side of the smaller oblique square is $xsqrt2$, how:




      Pythagorean theorem.




      The total green area is $x^2$, how:




      $$frac12 cdot xsqrt2cdot h_1+frac12 cdot xsqrt2 cdot h_2=frac12cdot xsqrt2cdot (h_1+h_2)=frac12cdot xsqrt2cdot xsqrt2=x^2.$$




      The total area of grey and green regions is $2x^2=16+32=48$, how:




      Green area is $x^2$ and grey area is $2cdot fracx^22=x^2$.




      Hence, the required area is $96-(16+20+32)=28$, how:




      the area of the large square $(4x^2)$ minus the total area of grey, green and white regions $16+20+32$.







      share|cite|improve this answer






















        up vote
        1
        down vote










        up vote
        1
        down vote









        Alternatively, refer to the figure:



        $hspace4cm$![enter image description here



        Let $x$ be the half of the side of the large square. Then the side of the smaller oblique square is $xsqrt2$, how:




        Pythagorean theorem.




        The total green area is $x^2$, how:




        $$frac12 cdot xsqrt2cdot h_1+frac12 cdot xsqrt2 cdot h_2=frac12cdot xsqrt2cdot (h_1+h_2)=frac12cdot xsqrt2cdot xsqrt2=x^2.$$




        The total area of grey and green regions is $2x^2=16+32=48$, how:




        Green area is $x^2$ and grey area is $2cdot fracx^22=x^2$.




        Hence, the required area is $96-(16+20+32)=28$, how:




        the area of the large square $(4x^2)$ minus the total area of grey, green and white regions $16+20+32$.







        share|cite|improve this answer












        Alternatively, refer to the figure:



        $hspace4cm$![enter image description here



        Let $x$ be the half of the side of the large square. Then the side of the smaller oblique square is $xsqrt2$, how:




        Pythagorean theorem.




        The total green area is $x^2$, how:




        $$frac12 cdot xsqrt2cdot h_1+frac12 cdot xsqrt2 cdot h_2=frac12cdot xsqrt2cdot (h_1+h_2)=frac12cdot xsqrt2cdot xsqrt2=x^2.$$




        The total area of grey and green regions is $2x^2=16+32=48$, how:




        Green area is $x^2$ and grey area is $2cdot fracx^22=x^2$.




        Hence, the required area is $96-(16+20+32)=28$, how:




        the area of the large square $(4x^2)$ minus the total area of grey, green and white regions $16+20+32$.








        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered 3 hours ago









        farruhota

        16.8k2735




        16.8k2735



























             

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