If a and b are parallel lines, and m∠3 = 128°, what is the measure of ∠8?

Question

Three lines are shown forming 8 angles.
Horizontal lines a and b are intersected by a diagonal line c from upper left to lower right.
Angles 1 through 4 are formed by lines a and c.
Angle 1 is above line a and left of line c.
Angle 2 is above line a and right of line c.
Angle 3 is below line a and left of line c.
Angle 4 is below line a and right of line c.

Angles 5 through 8 are formed by lines b and c.
Angle 5 is above line b and left of line c.
Angle 6 is above line b and right of line c.
Angle 7 is below line b and left of line c.
Angle 8 is below line b and right of line c.

(1 point)
Responses

134°
134°

52°
52°

54°
54°

49°

Answer 1

Since lines a and b are parallel, angles 3 and 8 are corresponding angles. Corresponding angles are congruent, meaning they have the same measure. Therefore, if m∠3 = 128°, then m∠8 must also be 128°.