Question

Does anyone know how to use the formula or do this?

Answer 1

Answer:

1440 ft²; 150 m²  

Step-by-step explanation:

Example 3

You are finding the lateral area (just the sides). You can ignore the triangular faces.

Thus, you are finding the surface area of the pink rectangle in Figure 1.

The formula is

Lateral surface = perimeter × height

                         =        P        ×     h

                         =    (3 × 12)   ×   40

                         =       36       ×   40

                            =        1440 ft²

Example 4

In this problem, the prism is sitting on its side, but the pentagonal faces are its top and bottom. You can ignore them.

Thus, you are calculating the area of the pink rectangle in Figure 2.

L = Ph

  = (5 × 6) × 5

  =    30   × 5

  =    150 m²