Question

An isosceles triangle has two equal side of length xcm each and a third side of 9cm. If it's perimeter is 24cm what is the van of x?

Answer 1

The perimeter of a isosceles triangle:

P = 2 a + b

where:

a = length of the two equal sides

b = third (unequal) side

P = 2 a + b = 24

In this case a = x , b = 9 cm.

2 x + 9 = 24

Subtract 9 to both sides

2 x + 9 - 9 = 24 - 9

2 x = 15

Divide both sides by 2

x = 7.5 cm

Answer 2

7.5cm