If area of circle is 49pi, find circumference in terms of pi
2007-07-08 06:31:05 · 13 answers · asked by hpdc90 1 in Science & Mathematics ➔ Mathematics
Area of a circle = pi*r^2 (r = radius)
Circumference = 2*pi*r
If Area = 49 pi, the radius = 7
The circumference is thus 14 pi.
2007-07-08 06:34:51 · answer #1 · answered by misscarinne 4 · 0⤊ 0⤋
the area of the circle is 49pi. the formula for the area of a circle is: A=Pi*r squared. so if pi isn't multiplied with 49, then 7 would be the radius.
now u have the radius, multiply 7 by 2= 14. if pi isn't multiplied with 14, the answer is 14pi.
2007-07-08 13:41:09 · answer #2 · answered by Zero 4 · 0⤊ 0⤋
It's given that area of circle is 49pi.. Recall formula to find the area of circle . It is...
Pi r^2
Area of circle = Pi r^2 = 49 Pi
Pi in both sides get cancelled to give
r^2 = 49
taking square root on both sides we get
r = 7
The formula to find the circumference of circle is 2 Pi r
so.. we know r = 7 ... plugging this in the formula we get
2 pi r = 2 pi (7) = 14 Pi
Circumference in terms of pi = 14 pi
Hope this helps :)
2007-07-08 13:38:53 · answer #3 · answered by kannan r 2 · 0⤊ 0⤋
Area of circle = pi.r^2 = 49.pi
So, r^2 = 49 and r = 7
Use that in the formula for circumference.
= pi.r
2.pi.7 = 14pi
14pi is the circumference.
2007-07-08 13:34:48 · answer #4 · answered by Swamy 7 · 0⤊ 0⤋
A= 49 pi
49 = r squared
r = 7
C = 2 pi R
C = 14 pi
2007-07-08 13:39:45 · answer #5 · answered by Bibs 7 · 0⤊ 0⤋
A=pi(r^2)
49pi=pi(r^2)
49=r^2
=>r=7
we have:
C=2A/r
C=2(49pi)/7
C=98pi/7
C=14pi
2007-07-08 13:38:46 · answer #6 · answered by God_Of_War 2 · 0⤊ 0⤋
if the area of the circle in 49pi, that means that it is the exact area. so try to find the exact circumference. hope tat helps.
2007-07-08 13:34:30 · answer #7 · answered by Anonymous · 0⤊ 0⤋
If you know that A=(pi)*(radius^2) and circumference=2*pi*(radius), and you already have the area, you can solve for the radius using the area formula, then plug into the formula for circumference.
2007-07-08 13:35:25 · answer #8 · answered by Anonymous · 0⤊ 0⤋
The area is always pi * radius^2 (or pi times the square of the radius), so the radius must be 7. The circumference is 2 * radius * pi, so it must be 14pi.
2007-07-08 13:34:37 · answer #9 · answered by Anonymous · 0⤊ 0⤋
Pi or Ï is a mathematical constant and a transcendental (and therefore irrational) real number, approximately equal to 3.14159, which is the ratio of a circle's circumference to its diameter in Euclidean geometry, and has many uses in mathematics, physics, and engineering. It is also known as Archimedes' constant (not to be confused with an Archimedes number) and as Ludolph's number.
2007-07-08 13:35:41 · answer #10 · answered by Anonymous · 0⤊ 0⤋