What is the circumference of a circle with an area of #49 pi# #i##n##ches^2#?

Question

48822 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-01-26T05:30:07

#44# #i##nches#

#Let# #radius# #o##f# #ci##rcl##e##=##r#
#Area# #o##f# #cir##c##l##e##=# #pir^2=49pi# #i##nches^2#

#Note# #th##at# #pi=22/7#

#rarrpir^2=49pi#

#rarrr^2=(49pi)/pi#

#rarrr^2=49#

#rarrr=sqrt49=7#

#So,we# #n##eed# #t##o# #fi##nd# #ci##rcu##mf##erence# #o##f# #ci##rcl##e#

#Ci##rcumference# #o##f# #ci##rcl##e# #=2pir#

#rarr2pir=2pi(7)=14pi#

#rarr=14*22/7=2*22=44# #i##nches#

Answer 2 · 2018-05-02T06:49:38

#C = 14pi = 43.982 ~~44# inches

To find the circumference, you need the radius.

You can find the length of the radius from the area.
(Divide by #pi# and then find the square root)

#pi r^2 =A" "rarrr = sqrt(A/pi)#

The radius is #r = sqrt((49cancelpi)/cancelpi)#

#r = sqrt49 = 7# inches

#C=2pir#

#C = 2pi(7)#

#C=14pi#

You can give the answer in this form using #pi# because that is how the area was given,

Or if you calculate it:

Using #pi ~~ 22/7#

#14 xx22/7#

#= 44# inches

Using the calculator value of #pi# which is more accurate gives:

#14pi =43.982# inches