CBSE Notes, Lectures

CBSE - Mathematics - Areas of Parallelograms and Triangles

Areas of Parallelograms and Triangles

NCERT Exercise Exercise 9.4

In the following figure, ABC and BDE are two equilateral triangles such that D is the mid-point of BC. If AE intersects BC at F, show that (iv) ar(BFE) =  ar(AFD)

In the following figure, ABC and BDE are two equilateral triangles such that D is the mid-point of BC. If AE intersects BC at F, show that

(iv) ar(BFE) =  ar(AFD)

ANSWER

(iv)It is seen that ΔBDE and ar ΔAED lie on the same base (DE) and between the parallels DE and AB.

∴ar (ΔBDE) = ar (ΔAED)

⇒ ar (ΔBDE) - ar (ΔFED) = ar (ΔAED) - ar (ΔFED)

∴ar (ΔBFE) = ar (ΔAFD)

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