The perimeter of an isosceles triangle is 36cm, the lateral side is 4cm larger than the base. Find the side of the triangle.

Let us take the length of the lateral side for x, then the length of the base is x – 4.

1. Considering that the triangle is isosceles, we compose an equation and determine the value of x:

2 x + (x – 4) = 36,

2 x + x – 4 = 36,

3 x = 36 + 4,

3 x = 40,

x = 40/3 cm or 13 1/3 cm.

2. Base length:

13 1/3 – 4 = 9 1/3 cm or 28/3 cm.

2. Check:

2 40/3 + 28/3 = 80/3 + 28/3 = 108/3 = 36 cm.

Answer: the length of the sides is 13 1/3 cm, the base is 9 1/3 cm.