Exercise 1 Page 656

Consider the given circle.

From the figure, we know that the circumference of the circle is 94.24 feet. The circumference C of a circle with radius r is calculated using the formula below.

C=2π r

Let's substitute 94.24 for C in the formula and solve the equation for r.

C=2 π r

Substitute

C= 94.24

94.24=2π r

▼

Solve for r

DivEqn

.LHS /2.=.RHS /2.

47.12=π r

DivEqn

.LHS /π.=.RHS /π.

47.12/π=r

UseCalc

Use a calculator

14.99876...=r

RoundInt

Round to nearest integer

15≈ r

RearrangeEqn

Rearrange equation

r≈15

We found that the radius of the circle is about 15. Now, to find the diameter, we can multiply the radius by 2. 15* 2=30ft The diameter of the circle is about 30 feet.