Question

In ΔABC ,D and E are points on the sides AB and

AC respectively ,such that DE ∥ BC .If AD =x

DB = x-2 ,AE = x+2 and EC = x-1, find the value​

Answer 1

Given: ABC is a triangle, DE || BC, AD = x, DB = x - 2, AE = x + 2 and EC = x - 1.

To find: x

In △ABC, we have

DE || BC

Therefore [By Thale's theorem]

AD/DB = AE/EC

AD × EC × = AE × DB

x(x-1) = (x-2)(x+2)

x2 - x = x2 - 4

x = 4