The triangle will have two 65° angles and a 50° angle
If the exterior angle is 115° then the interior angles has to be 65° since that adds up to 180°, a line. Since this is an isosceles triangle, there will be another angle that is 65°. All triangles add up to 180° so add the two angles (65 + 65 = 130) and subtract it from 180°.