How do you find the radius, diameter and circumference of a circle with an area of 64 cm2?

1 Answer
Jun 9, 2018

Answer:

#A=64cm^2#

#r~~4.51cm#

#d~~9.03cm#

#C~~28.36cm#

Explanation:

First let's find the radius #r# then we can solve the other questions:

Area formula:

#A_"circle" = pir^2#

#A/pi = r^2#

#+-sqrt(A/pi) = sqrt(r^2)#

we can ignore the negative solution because a radius can't be negative in length:

#r=sqrt(A/pi)=sqrt(64/pi)~~4.51#

Diameter formula:

#d=2r=2sqrt(64/pi)~~9.03#

Circumference formula:

#C_"circle" = 2pir#

#C= 2pisqrt(64/pi)~~28.36#