Calculate the perimeter of a rectangle if one of its sides is 5N cm and the diagonal is 13N cm.

From the condition, we know the length of one of the sides of the rectangle and it is 5 cm, and the length of the diagonal of the rectangle is also known – 13 cm. And we need to find the perimeter of the rectangle.

Let’s apply the formula for this:

P = 2 (a + b).

We know the length of one of the sides, and to find the length of the second side, we will consider a right-angled triangle, the hypotenuse of which is the diagonal of the rectangle, and the sides are legs.

We are looking for the length of the second side as an unknown leg.

c ^ 2 = a ^ 2 + b ^ 2;

a = √ (c ^ 2 – b ^ 2) = √ (13 ^ 2 – 5 ^ 2) = √ (169 – 25) = √144 = 12 cm.

We are looking for a perimeter:

P = 2 (5 + 12) = 2 * 17 = 34 cm.