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Envision Math 2.0: Grade 8, Volume 2 View details

Review

Exercise 3 Page 448

Use the formula for the surface area.

252π in.^2

Practice makes perfect

We want to find the surface area of a cylinder.

To calculate the surface area of a cylinder, we can use the following formula. S.A.=2π r^2 + 2π r h In this formula, r is the radius of the base and h is the height of the cylinder. In the diagram we can see that the diameter is 12inches. Therefore, the radius is 12÷ 2= 6inches. Substituting r with 6 and h with 15 into the formula, we can solve for S.A. Let's do it!

S.A.=2π r^2 + 2π rh

SubstituteII

r= 6, h= 15

S.A. = 2π ( 6)^2 + 2 π ( 6)( 15)

▼

Simplify right-hand side

CalcPow

Calculate power

S.A.=2π(36) + 2π (6)(15)

Multiply

S.A. = 2π(36) + 2π(90)

CommutativePropMult