What is the perimeter of this rectangular prism?

The answer is 12 x 2 + 7 x 2 = 24+12= 38.

Explanation: To find the perimeter of a rectangle, add the lengths of the rectangle's four sides. If you have only the width and the height, then you can easily find all four sides (two sides are each equal to the height and the other two sides are equal to the width). Multiply both the height and width by two and add the results.