McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
Study Guide and Review
Continue to next subchapter

Exercise 16 Page 872

Use the formula for the lateral area and surface area of a cylinder.

Lateral Area: ≈ 125.7 in.^2
Surface Area: ≈ 226.2 in.^2

Practice makes perfect

Consider the given solid.

The given solid is a cylinder. It has a radius of 4 inches and a height of 5 inches. Let's first calculate the lateral area and then the surface area.

Lateral Area

To calculate the lateral area, we can use the known formula where h is the height of the cylinder and r is the radius of the base. L=2π rh We are given both the height and the radius. Let's calculate the lateral area.
L=2π rh
L=2π ( 4)( 5)
Evaluate right-hand side
L=2π(20)
L=2* 20π
L=40π
L=125.66370...
L≈ 125.7
The lateral area is about 125.7 square inches.

Surface Area

To calculate the surface area of a cylinder, we can use the known formula where h is the height of the cylinder and r is the radius of the base. S=2π rh+2π r^2 Earlier, we found that 2π r h is about 125.7. Moreover, we have that r is 4. Let's substitute these values into the formula and calculate S.
S=2π rh+2π r^2
S≈ 125.7+2π( 4)^2
Simplify right-hand side
S≈ 125.7+2π (16)
S≈ 125.7+2* 16π
S≈ 125.7+32π
S≈ 125.7+ 100.53096...
S≈ 125.7+100.5
S≈ 226.2
The surface area of the cylinder is about 226.2 square inches.