Question

A composite figure is shown.

Answer 1

The surface area of the pyramid is 60 square feet

The surface area of the square prism is 480 square feet

The surface area of the cube is 180 square feet

The total surface area is 720 square feet

Area of Composite figures

From the question, we are to calculate the surface area of each part of the composite figure

• For the cube

Surface area of a cube is given by

$S = 6l^{2}$

Where $l$ is the length of a side

But only have 5 surfaces of the cube are part of the composite figure

∴ Surface area of the cubic part of the figure = $5l^{2}$

From the given information,

$l = 6 \ feet$

∴ Surface area of the cubic part of the figure = 5 × 6²

Surface area of the cubic part of the figure= 180 square feet

• For the square prism

The surface area of a square prism is given by the formula,

$S = 2l^{2} + 4lh$

Where $l$ is the length of the sides and

$h$ is the height

But the square surfaces are not part of the surface of the figure

∴ Surface area of the square prism in the figure = $2l^{2} + 4lh - 2l^{2}$

Surface area of the square prism in the figure = $4lh$

From the given information,

$l = 6 \ feet$

$h = 20 \ feet$

Thus,

Surface area of the square prism part of the figure = 4×6×20

Surface area of the square prism part of the figure = 480 square feet

• For the pyramid

The pyramid is a square pyramid

The surface area of a square pyramid is given by

$S = l^{2} + 2l\sqrt{\frac{l^{2} }{4}+h ^{2} }$

Where $l$ is the base length

and $h$ is the height of the prism

But the square base is not part of the surface of the figure

∴ Surface area of the pyramid part of the figure = $l^{2} + 2l\sqrt{\frac{l^{2} }{4}+h^{2} }\ - ( l^{2})$

Surface area of the pyramid part of the figure = $2l\sqrt{\frac{l^{2} }{4}+h^{2} }$

From the given information,

$l = 6 \ feet$

$h = 4 \ feet$

∴ Surface area of the pyramid part of the figure = $2(6)\sqrt{\frac{6^{2} }{4}+4^{2} }$

= $12\sqrt{\frac{36 }{4}+16}$

= $12\sqrt{9+16 }$

= $12\sqrt{25}$

= 12 × 5

= 60 square feet

Hence, the surface area of the pyramid is 60 square feet

Thus,

The total surface area = 180 square feet + 480 square feet + 60 square feet

The total surface area = 720 square feet

Hence, the total surface area is 720 square feet

Learn more on Calculating area of composite figures here: brainly.com/question/13175744

#SPJ1