To find the volume of a rectangular prism you would multiple the length, height, and width together. So, to find the area of one side divide one side length, 25, from the volume of 125 (125 ÷ 25), which equals 5 units.
this creates a polygon which can be shortened to be a triangle with side lengths 3 and 4 and the hypotenuse unknown. to find the side length you use the formula a^2 + b^2 = c^2