The perimeter of the triangle ABC is 62cm. BC = 17cm, AB = CD. Find the length of the side AB.

Given:
BC = 17 cm;

AB = CD =? cm;

P ABC = 62 cm.

An isosceles triangle is a triangle in which the two sides are equal in length. Equal sides are called lateral, and not an equal side is called the base.

Let’s take for x – the side AB of the triangle:

17 + x + x = 62;

2x = 62 – 17;

2x = 45

x = 22.5

Let’s check:

BC + AB + CD = P ABC;

17 + 22.5 + 22.5 = 62 – true

Answer: 22.5 cm length of side AB.