https://decimal-to-binary.com/ploschad-prizma.html?id=15

The area of the entire surface of a triangular prism with the base side a = 15 and height h = 5 equal to 419.85

Select the type of prism:
Side a: Height h:

Triangular prism

A regular triangular prism is a geometric figure whose base is an equilateral triangle.
Triangular prism surface area formula Triangular prism surface area formula where a is the side of the base, h is the height of the prism

Solution:
S =
6·a·h+a2·√3
2
=
6·15·5+152·√3
2
=
450+225·1.732
2
=
450+389.7
2
=
839.7
2
=
419.85

a: The area of the entire surface of a triangular prism with the base side a = 15 and height h = 5 equal to 419.85