Mathematics for IGCSE & O level - Geometrical Terms (Section 4 - No. 32)
If a sector of a circle has an angle of 60 degrees at the center and an arc length of 4.2cm, what is the circumference?
12.6 cm
25.2 cm
25.2 cm
4.2 cm
Explication
Using the ratio of the angle to 360 degrees, we find (60/360) = 1/6. If 4.2 cm represents 1/6 of the circumference, the full circumference is 4.2 * 6 = 25.2 cm