Equation for circumference of a circle is = 2*pi*r
56.52=2*pi*r
56.52/2*pi=r
r= 9
Equation for area of a circle = pi*r^2
A= pi * (9)^2
A= 81pi or 254.34
2007-12-30 18:20:28
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answer #1
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answered by ¿ /\/ 馬 ? 7
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So Pi*diameter = cirumference.
Diameter = 2*radius
3.14*d = 56.52 (divide by pi)
d = 56.52/3.14
d = 18
radius = d/2 = 9
area = Pi*radius squared.
radius*radius = 9*9 = 81
area = Pi*81=3.14 *81 =254.34
OK!
2007-12-31 02:20:50
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answer #2
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answered by Anonymous
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C = circunference
r = radius
C = 2 Ï r
r = C/2Ï
r = 56.52/6.28
r = 9
Area = A = Ï r ²
A = 3.14 (9) ²
A = 3.14 x 81
A = 254.34
2007-12-31 02:24:07
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answer #3
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answered by piano 7
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Area of circle: Ïr^2 (Ï * r * r)
(56.52 ÷ Ï Ã· 2)^2 x Ï
= (56.52 ÷ 3.14 ÷ 2)^2 x 3.14
= (18 ÷ 2)^2 x 3.14
= 9^2 x 3.14
= 81 x 3.14
= 254.34
(56.52 ÷ Ï) is to find the diameter
(56.52 ÷ Ï Ã· 2) is to find the r (radius)
(56.52 ÷ Ï Ã· 2)^2 means r^2 (r * r)
(56.52 ÷ Ï Ã· 2)^2 x Ï means Ïr^2
2007-12-31 02:29:38
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answer #4
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answered by An ESL Learner 7
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to find radius: (2)(pi)(r)
C= 2pir
56.52 /(2*3.14) =r
9=r
to find area = (pi)(r)2
= 3.14*9*9
= 254.34cm/m2
2007-12-31 04:17:50
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answer #5
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answered by Anonymous
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C = 2 Ï r
r = 56.52 / (2 Ï )
r = 9
A = Ï r ²
A = 254.34units ²
2007-12-31 03:26:10
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answer #6
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answered by Como 7
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the circumference equation is 2(pi)r
so you would divide the C by [2(pi)] to get r (radius)
you would then plug the radius in the area equation for a circle [(pi)r^2] <(pie time radius squared)
use ya calculator.
2007-12-31 02:19:44
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answer #7
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answered by Anonymous
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circumference is 2(pi)r = 56.52
so r = 56.52/2(pi) = 56.52X2X3.14 =9
area = (pi)(r)(r) = 3.14X9X9 =254.34
2007-12-31 02:19:46
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answer #8
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answered by manu b 1
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well first you need to find the equation for the circumfrance of the circle. and find the radius. then use the raidus in the area equation and it is easy.
2007-12-31 02:20:27
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answer #9
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answered by Unblest_Anubis 3
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