When they form conical piles, granular materials such as salt, gravel, and sand settle at different "angles of repose," depending on the shapes of the grains. One particular 13-foot tall cone of dry sand has a base diameter of 38.6 fee To the nearest tenth of a degree, what is the angle of repose of this type of dry sand?

A different conical pile of the same type of sand is 10 feet tall. What is the diameter of the cone's base?

Henley Landscaping Supply sells a type of sand with a 30° angle of repose for $32 per cubic yard. Find the cost of an 11-foot-tall cone of this type of sand. Show your work.