SOLUTION: Consider a circle whose size can vary. The circumference of the circle is always 2π times as large as its radius. Let r represent the radius of the circle (in feet) and let C
Algebra ->
Finance
-> SOLUTION: Consider a circle whose size can vary. The circumference of the circle is always 2π times as large as its radius. Let r represent the radius of the circle (in feet) and let C
Log On
Question 1122010: Consider a circle whose size can vary. The circumference of the circle is always 2π times as large as its radius. Let r represent the radius of the circle (in feet) and let C represent the circumference of the circle (in feet).
a. write a formula that expresses c in terms of r
b.Use your formula from part (a) to determine the circumference of a circle whose radius is 5 feet.
c. Write a formula that expresses r in terms of c
d. Use your formula from part (c) to determine the radius of a circle whose circumference is 31.4159 feet
c is the circumference
r is the radius
pi = 3.121592654
when r = 5, the circumference is 2 * pi * 5 = 10 * pi = 31.41592654
when c = 31.4159, r = c / (2 * pi) = 4.999995777.
note that they used the same circumference from part b in part d except that they rounded it to 4 decimal places which is why the radius didn't come out to be exactly 5; but it was close.
