Answer:
m∠3=80 degrees
m∠3=m∠1
Step-by-step explanation:
When two lines intersect, the opposite angles are equal. They are called vertical angles. That means for this problem:
m∠1 = m∠3 *Last option is true
m∠2 = 100° *Third option is false
A straight line is always 180°. When it is cut up, the sum of the angles is 180°. They are called suppementary angles. These are supplementary:
100° + m∠3 → m∠3 = 80° *Second option is true
m∠1 + 100° → m∠1 = 80° *First option is false
m∠1 + m∠2 → One or the other is 100° and 80°
m∠2 + m∠3 → One or the other is 100° and 80°
