Question

Each of the 2 equal sides of an isosceles triangle is twice as large as the third side. If the perimeter of the triangle is 30 cm, find the length of each side of the triangle.

Answer 1

Let the third side of an isosceles triangle be x.

Then, two other equal sides are twice.

So, both equal sides are 2x and 2x.

We know that, the perimeter of a triangle is sum of all sides of the triangle.

According to the question,

x + 2x + 2x = 30

⇒ 5x = 30

On dividing both sides by 5, we get

`(5x)/5 = 30/5`

⇒ x = 6 cm

∴ Third side = x = 6 cm

So, the other equal sides are 2x = 2 × 6 = 12 cm and 2x = 2 × 6 = 12 cm.