Answer/explanation:
Given:
m<8 = 23°
a. m<1 = 180° - m<8 (corresponding angles theorem and supplementary angles theorem)
m<1 = 180 - 23 = 157°
b. m<2 + m<1 = 180° (linear pair)
m<2 + 157° = 180°
m<2 = 180° - 153° = 23°
c. m<3 = m<1 (vertical angles are congruent)
m<3 = 157°
d. m<4 = m<2 (vertical angles are congruent)
m<4 = 23°
e. m<5 = m<1 (corresponding angles)
m<5 = 157°
f. m<6 = m<8 (vertical angles are congruent)
m<6 = 23°
g. m<7 = m<5 (vertical angles are congruent)
m<7 = 157°