A Round Plate $14$ In in Diameter Is to Have Ten Holes Drilled Through

Multiple Choice

A round plate $14$ in. in diameter is to have ten holes drilled through it. This is accomplished by creating a drawing for half the circle and the then "mirroring" the drawing for the other half of the circle. The $\frac { 1 } { 2 }$ in. diameter holes are to be equally spaced on a $10$ in. concentric circle in the top half of the plate. What is the angle A between the holes? What is the angle B between the horizontal and each of the end holes?

A) A = $36$ °, B = $30$ °
B) A = $72$ °, B = $36$ °
C) A = $60$ °, B = $30$ °
D) A = $60$ °, B = $18$ °
E) A = $36$ °, B = $18$ °