need help with this question

Question

A crew you’re supervising is installing a circular patio. In order to purchase the materials, they need to compute the area. The plans call for a diameter of 12 yards. The crew figures the area of the patio will be 37.68 square yards. Did the crew calculate the area correctly? If not, why?

Answer 1

The area of a circle is pi times radius squared. Pi = 3.14. The radius is 1/2 the diameter, so it is 6 yards. 6 squared = 36. 3.14 x 36 = 113.04 square yards. So, no they did not figure it correctly.

The answer they got, 37.68, is 3.14 x 12. They did not use radius and they did not square it.