Question

Find the surface area of the Rectangular Pyramid. Please see the attachment, of course 45 yards ^2 is not the correct answer. Thanks!

Answer 1

The correct option is (B) 39.8 yd²

Explanation:

A rectangular pyramid consists of four triangular lateral faces and a rectangle base. The sum of the area of the rectangle base and area of the four triangular lateral faces gives the surface area of rectangular pyramid. We use the following formula

Surface Area = Base Area + Lateral Area

where

Base Area = l × b

and

Lateral Area = 1/2 ls1 + 1/2 bs2 + 1/2 ls1 + 1/2 bs2 = ls1 + bs2

So

Surface Area = Base Area + Lateral Area SA = lb + ls1 + bs2

Putting the values we get 39.9

Answer 2

Surface area = 39 yards²

Explanation:

∵ the surface area of the pyramid = 1/2 pl + base area

Where p = perimeter of the base , l = slant height

∵ Area of the base = 3 × 3 = 9 yards²

∵ Perimeter of the base = 4 × 3 = 12 yards

∵ Slant height = 5 yards

∴ The surface area = 1/2 × 12 × 5 + 9 = 39 yards²