B Can I use the circle circumference formula for a sphere?

AI Thread Summary
The discussion clarifies that the circumference formula for a circle can indeed be applied to a sphere, specifically for calculating the circumference of a great circle. The user inquired about the correctness of their calculation, which yielded a circumference of 19.4 inches for a sphere with a radius of 3.09 inches. The response confirmed that this is accurate, as the formula for circumference remains consistent across both shapes. The key takeaway is that the circumference of a sphere is derived from its great circle, which is the largest circle that can be drawn on the sphere's surface. Understanding this concept simplifies the calculation process for spheres.
Perchaddition
Messages
2
Reaction score
0
Trying to calculate a circumference of a sphere from a radius of 3.09 inches. Is 19.4 a correct answer? Just ran numbers in the first circumference calculator I found http://calcurator.org/circumference-calculator/. Can I use the same formula for a sphere? What can I say ...Geometry is not my passion
 
Mathematics news on Phys.org
Perchaddition said:
Trying to calculate a circumference of a sphere from a radius of 3.09 inches. Is 19.4 a correct answer?
Yes.
Perchaddition said:
Just ran numbers in the first circumference calculator I found http://calcurator.org/circumference-calculator/. Can I use the same formula for a sphere? What can I say ...Geometry is not my passion
The circumference is always that of a circle. In the case of a sphere, it is the circumference of a great circle, circles of maximal circumference.
 
Reply
  • Like
  • Informative
Likes berkeman, Perchaddition and jedishrfu
Define circumference of a sphere.
 
Reply
  • Like
Likes jedishrfu and mfb
fresh_42 said:
Yes.

The circumference is always that of a circle. In the case of a sphere, it is the circumference of a great circle, circles of maximal circumference.
Thank you. Appreciate your explanation.
 

Thread 'Trigonometry problem of interest'

Seemingly by some mathematical coincidence, a hexagon of sides 2,2,7,7, 11, and 11 can be inscribed in a circle of radius 7. The other day I saw a math problem on line, which they said came from a Polish Olympiad, where you compute the length x of the 3rd side which is the same as the radius, so that the sides of length 2,x, and 11 are inscribed on the arc of a semi-circle. The law of cosines applied twice gives the answer for x of exactly 7, but the arithmetic is so complex that the...
View full post »

Thread 'Six Pencil Puzzle'

Is it possible to arrange six pencils such that each one touches the other five? If so, how? This is an adaption of a Martin Gardner puzzle only I changed it from cigarettes to pencils and left out the clues because PF folks don’t need clues. From the book “My Best Mathematical and Logic Puzzles”. Dover, 1994.
View full post »

Similar threads

B Constructing a Line Segment Equal to a Circle's Circumference?
Replies
6
Views
2K
I Is the Ratio of Circumference to Radius of a Circle Always Irrational?
Replies
19
Views
3K
I Possible simple formula for ellipse circumference
Replies
6
Views
2K
About probability of crossing a circle circumference by a needle
Replies
7
Views
2K
I Spherical trig - sphere radius from 6 lengths
Replies
8
Views
2K
MHB Tangent line to circle making 30º with a second circle
Replies
2
Views
2K
I Circumference of a circle on a spherical surface
Replies
7
Views
5K
B How can I accurately calculate pi using polygons and the concept of infinity?
Replies
2
Views
2K
MHB Find the exact shaded area of the region in 4 overlapping circles
Replies
1
Views
3K
Euclid's elements book 3 proposition 20
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top