The area of the rectangle is 144 cm2. What is the perimeter of a rectangle if the width is 4 times shorter than its length.

1. Let the width of the rectangle be x cm. Then, if the width is 4 times shorter than its length, then the length is 4x cm. According to the condition, the area of the rectangle is 144 cm² and is equal to S = x * 4 x. Let’s solve the resulting equation:

4x * x = 144;

4x² = 144;

x² = 144/4;

x² = 36;

x1 = – 6, does not fit, since the width cannot be negative;

x2 = 6;

Therefore, the width is 6 cm, and the length is 4 * 6 = 24 cm.

2. Find the perimeter of this rectangle:

P = 2 (a + b);

P = 2 * (6 + 24) = 2 * 30 = 60 cm.

Answer: the perimeter of the rectangle is 60 cm.