Final answer:
To prove that lines a and b are parallel, we need to show that the corresponding angles formed by the transversal c are congruent. Given that m∠3 = 45° and m∠5 = 3 ⋅ m∠3, we can substitute the value of m∠3 into the equation for m∠5 to find that angle 5 measures 135°.
Step-by-step explanation:
In order to prove that lines a and b are parallel, we need to show that the corresponding angles formed by the transversal c are congruent.
Given that m∠3 = 45° and m∠5 = 3 ⋅ m∠3, we can substitute the value of m∠3 into the equation for m∠5:
m∠5 = 3 ⋅ 45° = 135°
Therefore, the measure of angle 5 is 135°.