Question

Please help me out...

Answer 1

Answer:

70°

Step-by-step explanation:

CONSTRUCTION : join OC

Now, in triangle obc,

OB = OC(radii)

∴∠OBC = ∠OCB

∠OCB = 55°

∠BOC + ∠OBC +∠OCB = 180°

∠BOC = 180° - (∠OCB +∠OBC)

∠BOC = 70°

now, in ΔOBC and ΔODC,

BC = DC

OB = OD(radii)

OC = OC

∴ΔOBC ≅ ΔODC

∴∠BOC = ∠DOC = 70° (CPCT)

∠BOD = 70 + 70

∠BOD = 140°

we know that angle subtended at centre of the circle is twice the angle subtended at any point on the remaining part on the circle

∴∠BOD = 2 × ∠BAD

140° = 2 × ∠BAD

∠BAD = 140/2 = 70°