How to find the length of the side of a rectangle if its area is 18 cm²?

Recall that a rectangle is a geometric figure in which all angles are straight and equal. In this case, you should not confuse it with a square, in which, in addition, all sides are equal.

As a rule, only opposite sides of a rectangle are equal. Let us denote the length by a and the width by b. The area of the rectangle S = a * b.

Since we already know the area S = 18 cm², then to find the length of the side we need to express a: a = S / b. If we substitute the known data, we get a = 18 / b.

The width is almost the same: b = S / a = 18 / a.

Answer: a = 18 / b.