If the measure of each exterior angle of a regular polygon is 51(3/7), the ratio of the number of its diagonals to the

If the measure of each exterior angle of a regular polygon is 51(3/7), the ratio of the number of its diagonals to the number of its sides is.

(a)          13:6

(b)          5:2

(c)           3:1

(d)          2:1

Sol: