Question

Find the measure of the central angle that you would draw to represent 12.5% in a circle graph.

Answer 1

45°

Explanation:

360° is 100% (or 1, the whole)

so the ratio to use is 360:100 = x : 12.5

the proportionality between 360 and 100 must be the same as between the unknown value x and 12.5 (this is more or less the meaning in words), which leads to

x = (12.5*360)/100 = 45°

Another way of seeing it: 12.5% is 1/8 of 100% (therefore 1/8 of 360) so 360/8 = 45°