Answer:
the total surface area of the prism is 245.67
Explanation:
Given;
height of the triangular prism, h = 8
length of the triangular bases, = 7, 8, and 9
The total surface area of the prism is calculated as;
T.S.A = ph + 2B
Where;
p is the perimeter of the base
B is area of the base
P = 7 + 8 + 9 = 24
Area of the base can be calculated using Hero's formula;
T.S.A = (24 x 8) + 2 x 26.833
T.S.A = 192 + 53.666
T.S.A = 245.67
Therefore, the total surface area of the prism is 245.67