Gabriel makes a model of a pyramid with the dimensions shown.

A square pyramid. The square base has side lengths of 12 inches. The triangular sides have a height of 11 inches.

Gabriel wants to paint the model. How much paint will he need?

The area of the square base is

in.2.
The area of each triangular face is

in.2.
Gabriel will need

in.2 of paint.
please explain the method used