# One side is 12cm and the adjacent side is 3 times longer Calculate the perimeter and area of the rectangle.

We are given a rectangle, one side of which is 12 centimeters, and the other is three times this side. We need to find the perimeter and area of this rectangle, let’s start solving:

First, let’s find the second side, it will be equal to: 12 * 3 = 36 (centimeters). Then the width is 12 centimeters, and the length is 36 centimeters, since in a rectangle the width is always less than the length.

Denoting the length for the letter a, and the width for the letter b, it will be true that the perimeter is: P = (a + b) * 2, substitute the values and find it:

P = (12 + 36) * 2 = 48 * 2 = 96 centimeters

The area is found by the formula: S = a * b, therefore we find it by substituting the values:

S = 12 * 36 = 432 centimeters²;

Answer: perimeter 96 cm; area 432 cm²