Find the unknown side of the rectangle. if the diagonal of the rectangle is exactly the root of 113 and the other side is 7.

1. Let the unknown of the sides of the rectangle be equal to x.

2. The diagonal divides the rectangle into 2 equal right-angled triangles, being a hypotenuse in each triangle. Based on the Pythagorean theorem, we compose an equation and solve it:

x ^ 2 + 7 ^ 2 = 113;

x ^ 2 + 49 = 113;

x ^ 2 = 64;

x = 8.

Answer: The unknown side of this rectangle is 8.