Question

Find the missing length indicated
A) 25
B) 5
C) 8
D) 3

Answer 1

Given:

The figure of a triangle.

To find:

The missing length.

Solution:

Let x be the missing length.

Basic proportionality theorem(BPT): According to this theorem, if a line is parallel to the one side of a triangle then that the line intersects the other two sides of the triangle in the same ratio.

Using Basic proportionality theorem, we get

`(6)/(8-6)=(12-x)/(x)`

`(6)/(2)=(12-x)/(x)`

`3=(12-x)/(x)`

`3x=12-x`

Adding x on both sides, we get

`3x+x=12`

`4x=12`

`x=(12)/(4)`

`x=3`

The missing length is 3 Therefore, the correct option is D.