A full circle is 360°.
Divide the full circle into five congruent parts or arcs formed by 5 distinct points on a circle.
360 ° ÷ 5 = 72 °
Each arc has 72 degrees in measure.
Each central angle that intercepts the arc is also 72° in measure.
To convert degree measure to radians:
Degree measure × π = radian
180°
72 ° x π = radian
180°
= 72/180 radian or 2/5 radians