Answer:
828 in²
Step-by-step explanation:
To find the surface area of a triangular prism, you find the area of each side and add them together.
Find the area of each rectangular side:
Side 1 : 9 × 20 = 180 in²
Side 2 : 15 × 20 = 300 in²
Side 3 : 12 × 20 = 240 in²
Find the area of the triangular sides:
Area of a Triangle = [tex]\frac{1}{2}[/tex]bh
As you can see, 9 and 12 both work as the height/base for the triangular sides, so
Δ Side 1 = [tex]\frac{1}{2}[/tex]bh = [tex]\frac{1}{2}[/tex](9)(12) = 54
Δ Side 2 is also 54.
Add the areas of all the sides together:
180 + 300 + 240 + 54 + 54 = 828 in²
