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

If we have triangular pyramid with a side of s and all the faces and the base are equilateral triangles, then the formula for the total surface area is

SA = 3As + Ab

Where As is the area of the three faces

and

Ab is the area of the base

Since the triangles are equilateral, the surface area in terms of s is

SA = 3 (√3 / 4) s² + √3 / 4 s²

SA = √3 s²