The area of the rectangle is 64 m2, and its length is 4 times its width. What is the perimeter of the rectangle.

Let’s find the lengths of the sides of this rectangle.

Let’s denote by x the width of this rectangle.

According to the condition of the problem, the length of this rectangle is 4 times its width, therefore, the length of this rectangle is 4x.

According to the condition of the problem, the area of ​​this rectangle is 64 m2, therefore, we can draw up the following equation:

x * 4x = 64.

We solve the resulting equation and find the width of this rectangle:

4x² = 64;

x² = 64/4;

x² = 16;

x² = 4²;

x = 4 m.

Knowing the width of the rectangle, we find its length:

4x = 4 * 4 = 16 m.

Knowing the lengths of the sides of a given rectangle, we find its perimeter P:

P = 2 * (4 + 16) = 2 * 20 = 40 m.

Answer: the perimeter of this rectangle is 40 m.