 
                 
                InterviewSolution
 Saved Bookmarks
    				| 1. | `A B C D`is a parallelogram `X`and `Y`are the mid-points of `B C`and `C D`respectively. Prove that `a r( A X Y)=3/8a r(^(gm)A B C D)`GIVEN : A parallelogram `A B C D`in which `X`and `Y`are the mid-points of `B C`and `C D`respectively.TO PROVE : `a r( A X Y)=3/8a r(^(gm)a b c d)`CONSTRUCTION : Join `B Ddot` | 
| Answer» `In /_BCD` X and Y are midpoint of sides BC and CD XY||BD and XY=1/2BD `ar(/_CXY)=1/4*ar(/_ABC)` `ar(/_CYX)=1/8*ar(paral l elogram ABCD)-(1)` ParallelogramABCD and `/_ABX` AD||BX `BX=1/2BC` `/_ABX=1/4(||gram ABCD)-(2)` `ar(/_AYD)=1/4ar(||gram ABCD)-(3)` `ar(||gram ABCD)=ar(/_ABX)+ar(/_AYB)+ar(CYX)+ar(/_AXY)` `ar(AXY)=ar(||gram ABCD)-[ar(/_ABX)+ar(/_ATD)+ar(/_CYX)]` `ar(/_AXY)=(1-5/8) ar(||gram ABCD)` `ar(/_AXY)=3/8 ar(||gram ABCD)`. | |