Answer/Step-by-step explanation:
✅m<1 = 90° (right angle)
✅m<2 = 90° (<1 and <2 are supplementary, and also linear pair)
✅m<3 = 90° (<1 and <3 are supplementary, and also linear pair)
✅m<4 = 115° (vertical angles theorem)
✅m<5 + m<4 = 180° (linear pair)
m<5 + 115° = 180° (substitution)
Subtract 115 from each side
m<5 = 180 - 115
m<5 = 65°
✅m<6 = m<5 (vertical angles are congruent)
m<6 = 65° (substitution)
✅m<7 = m<1 + m<6 (exterior angle theorem)
m<7 = 90° + 65° (substitution)
m<7 = 155°
✅m<8 = 180 - m<7 (linear pair theorem)
m<8 = 180 - 155 (substitution)
m<8 = 25°
✅m<9 = m<7 (vertical angles are congruent)
m<9 = 155° (substitution)
