Mathematics for IGCSE & O level - Mensuration (Section 14 - No. 9)
What is the formula for calculating the circumference of a circle, given its radius (r)?
C = πr²
C = 2πr
C = πd
C = 4πr
คำอธิบาย
The circumference of a circle can be calculated using C = 2πr, where r is the radius.