2006-12-27 06:01:34 · 8 answers · asked by ladyfalkenburg@sbcglobal.net 1 in Science & Mathematics ➔ Mathematics
8 in. diameter, radius, or circumference?
2006-12-27 06:05:12 · answer #1 · answered by E 5 · 0⤊ 0⤋
The surface area of a sphere is calculated by
4 x pi x radius squared.
That means your 8" (assuming diameter here) ball has a surface area of roughly 201 square inches.
2006-12-27 14:06:46 · answer #2 · answered by Dennis R 2 · 0⤊ 0⤋
I presume you mean 8-inch diameter ball.
The volume (which you don't want to find, but which I'll say for information purposes) of a sphere is
V = (4/3) pi (r^3)
And the surface area of a sphere is
V = 4pi (r^2)
All you have to do is calculate r; since the diameter is 8, the radius r is 4.
V = 4pi (4^2) = 4pi(16) = 64pi
Unless the question specifically asks you to do it correct to a certain number of decimal places, leave your answer in its exact form.
Remember that if the diameter is in inches, your unit for surface area should be square inches.
V = 64pi square inches, or 64pi inches^2
2006-12-27 14:05:09 · answer #3 · answered by Puggy 7 · 0⤊ 0⤋
Rule: The area of the surface of a sphere (ball) equals four times the area of a circle of the same radius.
Formula is: S = 4pie r squared = pie x diameter squared
S = area if the surface
r = radius
d = diameter
Therefore: S = 3.1416 x 8 x 8
S = 201.0624 sq inches
2006-12-27 14:09:15 · answer #4 · answered by David C 2 · 0⤊ 0⤋
A = 4(pi)r^2. but is the ball 8 inches in diameter? in which case r = 4
2006-12-27 14:04:35 · answer #5 · answered by Shurikens Rule! 2 · 0⤊ 0⤋
surface area = 4 pi r^2 = 4 pi (8/2)^2 = 64 pi
2006-12-27 14:05:10 · answer #6 · answered by sahsjing 7 · 0⤊ 0⤋
A=4Ïr^2=4Ï8^2=256Ï=804.25 in^2
2006-12-27 15:44:46 · answer #7 · answered by yupchagee 7 · 0⤊ 0⤋
S = 4(pi)r(squared) = 4 x 3.14 x 4 x 4 = 201 sq. inches
2006-12-27 14:09:26 · answer #8 · answered by Laguna Tim 2 · 0⤊ 0⤋