Find the area of a rectangle with a perimeter of 36 cm and a length of 8 cm.

1) A rectangle is a quadrangle in which two opposite sides are equal and all four corners are the same. The long side of the rectangle is called the length of the rectangle (a), and the short side is called the width of the rectangle (b). The perimeter of a rectangle is the sum of the lengths of all sides of the rectangle: P = 2 (a + b). Formula for the area of a rectangle in two sides: S = a · b.

2) P = 2 (a + b); 36 = 2 * 8 + 2b; 36 = 18 + 2b; 18 = 2b; b = 9 cm.

3) S = a b = 9 * 8 = 72 cm ^ 2.

Answer: 72 cm ^ 2.