If M and N are parallel and angle 1 is 135°, what is the sum of angle 6 and angle 8
Since M and N are parallel lines, alternate interior angles are congruent. Therefore, angle 6 is also 135°.
Since angle 1 and angle 6 are supplementary angles (they sum up to 180°), angle 8 is 180° - angle 1 = 180° - 135° = 45°.
Therefore, the sum of angle 6 and angle 8 is 135° + 45° = 180°.