Answer:
The measures of the four angles at B are
m∠EBC = 34°
m∠ABH = 34°
m∠EBA = 146°
m∠CBH = 146°
Explanation:
∵ AC // DF
∵ HG is the transversal
∴ m∠GEF = m∠EBC ⇒ corresponding angles
∵ m∠GEF = 34°
∴ m∠EBC = 34°
∵ GH intersects AC at B
∴ m∠EBC = m∠ABH ⇒ vertically opposite angles
∵ m∠EBC = 34°
∴ m∠ABH = 34°
∵ B ∈ AC
∴ ∠EBC and ∠EBA formed a pair of linear angles
∵ The sum of the measures of the pair of linear angles is 180°
∴ m∠EBC + m∠EBA = 180°
→ Substitute m∠EBC by 34°
∴ 34 + m∠EBA = 180
→ Subtract 34 from both sides
∵ 34 - 34 + m∠EBA = 180 - 34
∴ m∠EBA = 146°
∵ ∠EBA and ∠CBH are vertically opposite angles
∴ m∠EBA = m∠CBH
∵ m∠EBA = 146°
∴ m∠CBH = 146°