Exercise 27 Page 873

Consider the given sphere.

The surface area of a sphere is four times the product of π and the square of the radius. S.A.=4π r^2 In the diagram we can see that the radius is 9 meters. Therefore, we can substitute 9 for r in the formula and simplify the right-hand side.

S.A.=4π r^2

Substitute

r= 9

S.A.=4π ( 9)^2

▼

Simplify right-hand side

CalcPow

Calculate power

S.A.=4π(81)

CommutativePropMult

Commutative Property of Multiplication

S.A.=4* 81π

Multiply

S.A.=324π

UseCalc

Use a calculator

S.A.=1017.87602...

RoundDec

Round to 1 decimal place(s)

S.A.≈ 1017.9

The surface area of the given sphere is about 1017.9 square meters.