Thread: How do you find the volume of the smallest rectangular prism that can completely contain the cylinder?

If a right cylinder has diameter d and height h what is the volume of the smallest rectangular box that completely contains the cylinder. The correct answer is d^2*h and the answer key states that it is because a square would fit in the bottom circle with side d but if the diameter is d how would two diameters meet at one point and form a right angle?

Draw a square and a circle that fit in it. The side of the square is the diameter of the circle. Call them d and that's it.