abcd is a llgm x and y are the mid point of bc and cd
to prove
ar(axy)= 3/8(ar abcd)
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i didnt understand q plzz ex0lain it properly
aniketkabaddi01:
abcd is a prallelogram in which x and y are the mid points of bc and cd ... join axy now to prove Ar(axy)= 3/8 ar(abcd)
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Join points B and D.
Since X and Y are the mid points of sides BC and CD respectively,
In ∆BCD, XY|| BD and XY =1/2 BD.
⇒ ar (∆CYX) = 1/4ar (∆DBC)
⇒ ar (∆CYX) = 1/8ar (||gm ABCD)
[Area of parallelogram is twice the area of triangle made by the diagonal]
Since parallelogram ABCD and ∆ABX are between the same parallel lines AD and BC and BX = 1/2BC.
ar (∆ABX) = 1/4ar (||gm ABCD)
Similarly, ar (∆AYD) = 1/4 ar (||gm ABCD)
Now, ar (∆AXY) = ar (||gm ABCD) – [ar (∆ABX) +ar (∆AYD) +ar (∆CYX)]
ar llgm ABCD - 1/4ar (||gm ABCD) +1/4 ar (||gm ABCD) + 1/8 ar (||gm ABCD)]
=ar llgm ABCD - 5/8 llgm ABCD
=3/8 llgm ABCD
Since X and Y are the mid points of sides BC and CD respectively,
In ∆BCD, XY|| BD and XY =1/2 BD.
⇒ ar (∆CYX) = 1/4ar (∆DBC)
⇒ ar (∆CYX) = 1/8ar (||gm ABCD)
[Area of parallelogram is twice the area of triangle made by the diagonal]
Since parallelogram ABCD and ∆ABX are between the same parallel lines AD and BC and BX = 1/2BC.
ar (∆ABX) = 1/4ar (||gm ABCD)
Similarly, ar (∆AYD) = 1/4 ar (||gm ABCD)
Now, ar (∆AXY) = ar (||gm ABCD) – [ar (∆ABX) +ar (∆AYD) +ar (∆CYX)]
ar llgm ABCD - 1/4ar (||gm ABCD) +1/4 ar (||gm ABCD) + 1/8 ar (||gm ABCD)]
=ar llgm ABCD - 5/8 llgm ABCD
=3/8 llgm ABCD
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