Answer:
Explanation:
To get the area of the triangle sides, we use the formula
In words, this is base · height ÷ 2
After using this formula we find the surface area of the triangle sides is 54
Of course because there are two sides, we do 54 + 54 = 108
For the base of the prism, we do 12 · 18, which equals 216
For the back, we do 9 · 18, which equals 162
For the top, we do 15 · 18, which equals 270
Now that we have the individual areas of all the faces, we add them together. Doing this, we get