The rectangle is 10 centimeters long and 4 centimeters wide. Its area is 1/10 of the area of the square.

The rectangle is 10 centimeters long and 4 centimeters wide. Its area is 1/10 of the area of the square. Find the area of the square.

1. The area S of a rectangle with sides a and b is equal to the product of the sides: S = a * b.

2. The area of the rectangle according to the condition of the problem is S = 10 * 4 = 40 sq. Cm.

3. This area is 1/10 of the area of the square. That is, if the area of a square is denoted by Q, then S = 1/10 * Q.

3. Multiply both sides of the equality by 10. We get Q = 10 * S = 10 * 40 = 400 sq. Cm.

Answer: the area of the square is 400 sq. Cm.