Answer:
The diagram shows that m∠1 = 90.
∠1 and ∠3 are vertical angles. Their measures are equal, so m∠3 = 90.
∠1 and ∠2 are supplementary.
m∠1 + m∠2 = 180 Definition of supplementary angles
90 + m∠2 = 180 Substitute 90 for m∠1.
m∠2 = 90 Subtract 90 from each side.
∠2 and ∠4 are vertical angles. Their measures are equal, so m∠4 = 90.
ANSWER: m∠2 = m∠3 = m∠4 = 90
Perpendicular Lines
