The perimeter of an isosceles triangle is 16 cm larger than its base and 2.5 times larger than the lateral side.

The perimeter of an isosceles triangle is 16 cm larger than its base and 2.5 times larger than the lateral side. find a foundation

Let the base of this isosceles triangle be x, the lateral side – y, P – the perimeter. By the condition of the problem, we can write:

1) x + 16 = P,

2) 2.5 * y = P,

3) x + 2 * y = P.

Using the method of algebraic addition, subtract the third from the first equation, we get:

x – x + 16 – 2 * y = 0;

2 * y = 16;

y = 16/2 = 8 cm – side.

Find the perimeter:

P = 2.5 * y = 2.5 * 8 = 20 cm.

From the first equation we find x:

x = P – 16 = 20 – 16 = 4 cm – the base of this isosceles triangle.