Geometry Practice Test 1

In ΔABD ⇒ ∠A +∠D+∠ABD = 180°
∠A = 50°
∠D = 90°
∠ABD = 180° − (90° + 50°)
∠ABD = 40°
In ΔAOB,
∠BAO+∠ABD+∠AOB = 180°
25° + 40° +∠AOB = 180°
∠AOB = 180° − (25° + 40°)
= 180° − 65°
∠AOB = 115°

Similarly, AOC = 115°
∠AOB+∠AOC+∠BOC = 360°
115° +115° +∠BOC = 360°
∠BOC = 360° − 230°
∠BOC = 130°