The perimeter of the rectangle is 48 cm. The three sides of which are 36 cm. Find the length of sides a and b

We write the first condition of the problem by the expression for the perimeter:

2 x A + 2 x B = 48.

We write the second condition of the problem as follows:

A + 2 x B = 36.

The result is a system of equations. The easiest way to solve it is by subtracting the second from the first equation. We get immediately A:

A = 12 (cm).

Now from the second equation we express B:

B = (36 – A) / 2;

B = 24/2;

B = 12 (cm).

Answer: the given rectangle is a square, where A = B = 12 cm.