One of the exterior angles of an isosceles triangle is 80 degrees. Find the angle between the base of the triangle and the altitude drawn to one of the legs.
If the exterior angle is 80, then the top angle is 100 and the congruent angles are 40 each. Because there's an altitude there is a right triangel with one angle 90 and the other 40. The other angle is 50 degrees.
+130 
