Find the sides of an isosceles triangle if its perimeter = 20 cm, and its side is 1 cm larger than its base.

An isosceles triangle is a triangle whose sides are equal. Let’s solve the problem using the equation, where:

x cm – the base of an isosceles triangle;

(x + 1) cm – the lateral side of an isosceles triangle (since it is 1 cm larger than the base);

Let’s compose and solve the equations, knowing the perimeter of the triangle:

x + (x + 1) + (x + 1) = 20;

x + x + 1 + x + 1 = 20;

3x + 2 = 20;

3x = 20 – 2;

3x = 18;

x = 18/3;

x = 6 cm – the base of an isosceles triangle;

x + 1 = 6 + 1 = 7 cm – sides of an isosceles triangle.

Answer: 6 cm, 7 cm, 7 cm.