Answer:
18. ∠AED= ∠BEC (vert. opp. ∠s)
2x -11= 105
2x= 105 +11
2x= 116
x= 116 ÷2
x= 58
∠AEB= 180° -105° (adj. ∠s on a str. line)
∠AEB= 75°
∠BEC= 105° (vert. opp. ∠s)
∠CED= ∠AEB (vert. opp. ∠s)
∠CED= 75°
∠AED= 105° (given)
19. ∠AEB +∠BEC= 180° (adj. ∠s on a str. line)
6x +19 +x= 180
7x +19= 180 (simplify)
7x= 180 -19 (-19 on both sides)
7x= 161 (simplify)
x= 161 ÷7
x= 23
∠AEB= 6(23) +19
∠AEB= 157°
∠BEC= 23°
∠CED= ∠AEB (vert. opp. ∠s)
∠CED= 157°
∠AED= ∠BEC (vert. opp. ∠s)
∠AED= 23°
