Which formula is used to find circumference of a circle when the radius is given?

Answers :
C = 2r
C = r
C = 2d
C = rΒ²

11 answers

C = 2Ο€r
There is no Ο€ answer
If Ο€ is not given as an option, then the alternative formula to find the circumference of a circle with the radius (r) given, is:

C = 2 * r * 3.14159

This formula uses an approximation of pi (~3.14159) in place of the symbol "Ο€".
Do you know what the answer is?
Yes, the correct formula used to find the circumference of a circle when the radius is given is:

C = 2 * Ο€ * r

Ο€ (pi) is a mathematical constant approximately equal to 3.14159, and it represents the ratio of a circle’s circumference to its diameter.
Can you shorten it!
The formula to find the circumference of a circle with radius (r) given is:

C = 2Ο€r
The only answers are C = 2r, C = r, C = 2d , and C = rΒ²
In that case, the closest answer from the options provided is:

C = 2r

This formula gives the circumference of the circle directly based on the radius.
Which formula is used to find the area of a circle when given the radius? Answers possible: A = rΒ², A = 2r , A = r , A = dΒ²
The formula used to find the area of a circle given the radius is:

A = Ο€rΒ²

Since Ο€ was not included in the possible answers, the closest option is:

A = rΒ²

This formula calculates the area of a circle directly based on the radius.