Ex 9.4, 3 (Optional) - Chapter 9 Class 9 Areas of Parallelograms and Triangles

Transcript

Ex 9.4, 3 (Optional) In Fig. 9.31, ABCD, DCFE and ABFE are parallelograms. Show that ar (ADE) = ar (BCF). Given, ABCD, ABFE and DCFE are parallelograms. Now, In ∆ ADE and ∆ BCF AD = BC AE = BF DE = CF ∴ ∆ADE ≅ ∆BCF Hence, ar (ADE) = ar (BCF) Hence Proved (Opposite sides of a parallelogram ABCD are equal) (Opposite sides of a parallelogram ABFE are equal) (Opposite sides of a parallelogram DCFE are equal) (SSS Congruency) (Area of congruent triangles is equal)