Question

The surface area of this triangular pyramid, whose base and lateral faces are congruent equilateral triangles, is __ square inches.

Answer 1

The surface area is equal to
`390\ in^(2)`

Explanation:

The surface area of the triangular pyramid is equal to the area of its four triangular faces

so

In this problem

`SA=4[(1)/(2)(b)(h)]`

we have

`b=15\ in`

`h=13\ in`

substitute the values

`SA=4[(1)/(2)(15)(13)]=390\ in^(2)`