You want to build a plant stand with three equally spaced circular shelves. You want
the top shelf to have a diameter of 6 inches and the bottom shelf to have a diameter
of 15 inches. The diagram below shows a vertical cross section of the plant stand.
What is the diameter of the middle shelf?

You want to build a plant stand with three equally spaced circular shelves You want the top shelf to have a diameter of 6 inches and the bottom shelf to have a class=