In the following diagram, line l and line m are parallel to each other. line t is a transversal intersect line l and line m.
a student named alex is asked to solve for the degree measure of angle 4, given that the measure of angle 6 is 40°. alex tells the teacher that the m∠4 = 40°.

explain alex's mistake. in your explanation, be sure to include the key terms "corresponding angles", “parallel lines”, and "transversal" in your explanation.

b. calculate the correct measure of angle 4.