Find the area and perimeter of a rectangle with sides 13 and 3 times larger.

First of all, let’s write down the formulas for determining the perimeter (pay attention to the spelling!) Of a rectangle:

S = a * b;
P = 2 * (a + b).

Ho first calculate the length of the second side of the rectangle. T. to. it is 3 times larger than the first, equal to 13 cm, then it is equal to:

13 * 3 = 39 (cm).

Now we can calculate the perimeter and area of the desired rectangle using the marked formulas.

P = 2 * (a + b) = 2 * (13 + 39) = 2 * 52 = 104 (cm).
S = a * b = 13 * 39 = 507 (cm 2).

Answer: P = 104 cm, S = 507 cm 2.