Answer:
The surface area is [tex]324\ in^{2}[/tex]
Step-by-step explanation:
we know that
The surface area of the triangular prism is equal to
[tex]SA=2B+PL[/tex]
where
B is the area of the triangular base
P is the perimeter of the triangular base
L is the length of the prism
Find the area of the base B
[tex]B=\frac{1}{2}(12)(9)=54\ in^{2}[/tex]
Find the perimeter of the base P
[tex]P=(12+9+15)=36\ in[/tex]
we have
[tex]L=6\ in[/tex]
substitute in the formula
[tex]SA=2(54)+(36)(6)=324\ in^{2}[/tex]
