Answer:
Answer = 93.6
Explanation:
frist multipy 9 x 13 to get 117 than divided it by 2 = 58.5, than times it by 3 since there is three sides.
(58.5 x 3 is 175.5)
Than for the base multipy 7.8 x 9 = 70.2, but since its a tri, divided it by 2 = 35.1.
Add 58.5 and 35.1 to get 93.6