Question extracted from RD sharma of class 10th, Chapter no. 4

Chapter name:- Triangles

Exercise :- 4.2

This is very basic and important questions. And has been asked in several times in exams.

We have a triangle ΔABC, in which D and E are points on the sides AB and AC respectively such that DE || BC.

Also it is given AD = 8 cm, AB = 12 cm and AE = 12 cm,

Now we have to find CE.

learning CBSE maths in effective way.

RD sharma, DHANPAT RAI publication

Given:Length of side AD = 8 cm, AB = 12 cm, and AE = 12 cm.

To find: Length of side CE.

By using Thales Theorem, we get

AD/BD = AE/CE – equation 1

Now, putting values in equation 1,

8/4 = 12/CE

8 x CE = 4 × 12 cm

CE = (4 × 12)/8 cm

CE = 48/8 cm

∴ CE = 6 cm

Therefore, Length of side x is 6 cm