This is another one for the "impossible geometry question" file.
Answering the last question first, the sum of exterior angles of any convex polygon is 360°.
This fact tells us that the sum of interior angles is 10*180° - 360° = 1440°. Without additional information, we do not know the measure of each interior or exterior angle.
If we assume all angles are equal, then
Each interior = 1440°/10 = 144°
Each exterior = 180° -144° = 36°
