Answer:
690 sq in
Step-by-step explanation:
SA = LA + 2B where LA is the lateral area and B is the area of the base
The triangular base has an area of
B = 1/2bh 1/2(5)(12) = 30
LA = ph where p is the perimeter of the base and h is the height of the prism
LA = (12 + 5 + 13)(21) = 30(21) = 630
SA = 630 + 2(30) = 630 + 60 = 690 sq in
