All green angles measure b, so all green angles are congruent.
All pink angles are congruent and measure a.
There are 4 pink angles and 4 green angles.
The sum of the measures of the all central angles of a circle is 360 deg.
4a + 4b = 360
We are told that b = 50.
4a + 4(50) = 360
4a + 200 = 360
4a = 160
a = 40
Each pink angles measures 40 deg.
