Answer:
if exterior angle is 10 degrees, then interior angle is 180 -10 = 170 deg.
Each trinaglke inside the polygon will be isosceles with two angles of 170/2 - 85 degrees each.
So, angle at centre = 180 -170 = 10 deg.
Ttal angle at centre = 360 deg.
No of sides = 360 /10 = 36 sided polygon.
b) Sum of interior angles is given by (2N-4) Right angles
So: 9900 = (2N-4)x90 = 180N - 360
180N = 9900 +360 = 10260
N = number of sides = 10260 / 180 = 57 sides