A sector of a circle of radius 21 cm has a central angle of 60°. What is the area of the sector in square cm? (Use π = 22/7.)

The whole circle has area $(22/7)\times 21^2=1386$ sq cm. A 60° sector is 60/360 = 1/6 of the circle, so its area = 1386/6 = 231 sq cm. 1386 is the entire circle with the fraction forgotten; 462 comes from writing the fraction as θ/180 = 1/3 instead of θ/360; 22 is the ARC LENGTH, $(1/6)\times 2\times (22/7)\times 21$, which is a length and not an area.