The measure of the third angle of the triangle is 100°.
Since two angles are already provided in the problem. We just have to deduct the sum of these angles to get the angle measurement of the third angle.
35° + 45° = 80°
180° - 80° = 100°
Bear in mind that the sum of the interior angles of a triangle is always equal to 180°. So to find the missing measurement of every angle the equation should always be equal to 180°.
angle 1 + angle 2 + angle 3 = 180°