Math Is Fun Forum
Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2009-10-07 11:13:23
- childboo
- Member
- Registered: 2009-10-07
- Posts: 2
circumference
a radius of 2m is 4 but how do get that answer
Offline
#2 2009-10-07 11:28:30
- mathsyperson
- Moderator
- Registered: 2005-06-22
- Posts: 4,900
Re: circumference
The formula for the circumference of a circle is 2πr, where r is the circle's radius.
If you have a circle with radius 2m, its circumference will be 4π m, or around 12.5m.
Why did the vector cross the road?
It wanted to be normal.
Offline
#3 2009-10-09 00:11:04
- childboo
- Member
- Registered: 2009-10-07
- Posts: 2
Re: circumference
i don't understand where four comes from do u add or what tha's what i do o understand
Offline
#4 2009-10-09 03:04:36
- mathsyperson
- Moderator
- Registered: 2005-06-22
- Posts: 4,900
Re: circumference
The 4 is there because it's double the radius.
To get circumference, multiply the radius by 2 and then multiply that by π.
Why did the vector cross the road?
It wanted to be normal.
Offline
Pages: 1