217k views
2 votes
Find the surface area of the figure to the nearest whole number.

Find the surface area of the figure to the nearest whole number.-example-1
User Motla
by
4.6k points

1 Answer

4 votes

Answer:

Explanation:

The surface area of the figure is the sum of the areas of each of the 9 faces.

Area formula

We can let b represent the edge length of the base, s represent the vertical height of a side wall, and h represent the slant height of the triangular top face.

The formula for the area of each of the 5 rectangular shapes is ...

A = LW

So their total area is ...

rectangular areas = base area + 4×sidewall area

= b² +4bs

The formula for the area of each of the triangular shapes is ...

A = 1/2bh

There are 4 of them, so their total area is ...

triangular areas = 4×(1/2bh) = 2bh

Then the surface area of the figure is ...

surface area = rectangular areas + triangular areas

SA = b² +4bs +2bh = b(b +4s +2h)

Application

Filling in the given dimensions, we find the surface area to be ...

SA = (4.5 ft)(4.5 ft + 4(6 ft) +2(3.3 ft)) = (4.5 ft)(35.1 ft)

SA = 157.95 ft² ≈ 158 ft²

The surface area of the figure is about 158 square feet.

User Sam Gammon
by
4.4k points