Triangle ABC isosceles perimeter of triangle ABC = 25.5 cm, the base is 2 times less than the lateral side, find the sides.

The given triangle is isosceles. So it consists of two identical sides – the hips and one more – the base. If we declare the length of the thigh x, then, according to the condition, the length of the base will be x / 2, and the perimeter will be x + x + x / 2 or 25.5 cm. Let us solve the obtained with respect to x:

x + x + x / 2 = 25.5;

x * (1 + 1 + 1/2) = 25.5;

x * 2.5 = 25.5;

x = 25.5 / 2.5;

x = 255/25;

x = 51/5;

x = (50 + 1) / 5;

x = 10 + 1/5;

x = 10 + 0.2;

x = 10.2 (cm).

We got the length of the thigh, which means the base:

10.2: 2 = 5.1 (cm).

Answer: the lengths of the sides are 10.2; 10.2 and 5.1 cm.