If two parallelograms ABCD and ABEF are on the same base AB and between the same parallels AB and FC, then prove that ar(ABCD) = ar(ABEF)
Open in App
Solution
Two parallelograms ABCD and ABEF on the same base AB and between the same parallels AB and FC.
To prove : ar(ABCD) = ar(ABEF) Proof : In △ADF and △BCE, we have
AD=BC [Opposite sides of a ||gm] AF=BE [Opposite sides of a ||gm] ∠DAF=∠CBE[AD||BC and AF||BE]
[Angle between AD and AF = Angle between BC and BE] ∴△ADF≅△BCE [By SAS congruency] ∴ar(ADF)=ar(BCE)...(i) ∴ar(ABCD)=ar(ABED)+ar(BCE) =ar(ABED)+ar(ADF) [Using (i)] =ar(ABEF). Hence, ar(ABCD)=ar(ABEF).