If the radius of a circle proportional to the circumference of the circle. justify your answer. if the radius of a circle is 18 miles 1. what is the measure of the diameter. 2. what is the measure of the circumference, exactly in terms of pi. 3. what is approximate measure of the circumference, to the nearest tenth of a mile.

circumference of a circle (C)

C = πd or 2πr ( because d 2 x r)

r= 18 miles given

d= diameter

r= radius

d = 2 x r

d = 2 x 18 = 36 miles

2) C = πd

C = 3.14 x 36 = 113.04 miles

3) approximate measure of C = 22/7 x 36= 113.14 miles

circle area = pi * radius^2

if diameter = 10 then radius = 5

circle area = pi * 5^2

circle area = pi * 25

circle area = 78.5398163397 square units

step-by-step explanation: