Exercise 44 Page 721

First evaluate the radius of the pond using the given circumference.

≈ 93.12 feet

Practice makes perfect

We are given that a brick pack is being installed around a circular pond and we know that the outer edge of the path is going to be 4 feet from the pond all the way around. Let's sketch a diagram of this situation. Let r be the radius of the pond.

Since the pond has a circumference of 68 feet we can find r using the circumference formula.

C=2π r

Substitute

C= 68

68=2π r

DivEqn

.LHS /2π.=.RHS /2π.

34/π=r

RearrangeEqn

Rearrange equation

r=34/π

UseCalc

Use a calculator

r=10.8225...

RoundDec

Round to 2 decimal place(s)

r≈ 10.82

The radius of the pond is approximately 10.82 feet.

This means that the radius of the path is 4+10.82=14.82 feet. Using this radius we can evaluate the circumference of the path.

C=2π r

Substitute

r= 14.82

C=2π(14.82)

UseCalc

Use a calculator

C=93.1168...

RoundDec

Round to 2 decimal place(s)

C≈ 93.12

The circumference of the path is approximately 93.12 feet.

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Exercises p.719-723

Exercise 44 Page 721

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