Question

A

= 13 m,

b

= 9 m and

c

= 2 m for the triangle shown below.


Work out the value of

x

, giving your answer as an exact surd.

The diagram is not drawn accurately

Answer 1

2√21

Explanation:

let the sides of bigger triangle be a, b and d.

then,

a²= b² + d² [ by Pythagoras theorem]

13² = 9² + d²

d² = 13² - 9²

d²= 169 - 81

d² = 88

d = √88

Now, the sides of smaller triangle are c, x, and d

by Pythagoras theorem,

d² = c²+x²

(√88)² = 2² + x²

88 - 4 = x²

x² = 84

x = √84

x= 2x2x3x7

x = 2√21

Therefore, the value of x is 2√21

Hope it's helpful..