<u>Given</u>:
The base of the triangle is b = 3 feet.
The height of the triangle is h = 4 feet.
The other side of the triangle is 5 feet.
The height of the triangular prism is 20 feet.
We need to determine the surface area of the triangular prism.
<u>Surface area of the triangular prism:</u>
The surface area of the triangular prism is given by the formula,
![SA=bh+(s_1+s_2+s_3)H](https://tex.z-dn.net/?f=SA%3Dbh%2B%28s_1%2Bs_2%2Bs_3%29H)
where b is the base of the triangle,
h is the height of the triangle,
s₁ , s₂ and s₃ are the sides of the triangle and
H is the height of the triangular prism.
Substituting the values, we get;
![SA=(3)(4)+(3+4+5)(20)](https://tex.z-dn.net/?f=SA%3D%283%29%284%29%2B%283%2B4%2B5%29%2820%29)
![SA=12+(12)(20)](https://tex.z-dn.net/?f=SA%3D12%2B%2812%29%2820%29)
![SA=12+240](https://tex.z-dn.net/?f=SA%3D12%2B240)
![SA=252 \ ft^2](https://tex.z-dn.net/?f=SA%3D252%20%5C%20ft%5E2)
Thus, the surface area of the triangular prism is 252 ft²