Question

AD, BE, and CF are all diameters of the circle. The measure of angle AOB is 40 degrees. The measure of angle DOF is 120 degrees.

BOC= ___ degrees.
COD= ___ degrees.

Answer 1

∠ BOC = 80°, ∠ COD = 60°

Explanation:

∠ AOC = ∠ DOF = 120° ( vertical angles ), then

∠ BOC = ∠ AOC - ∠ AOB = 120° - 40° = 80°

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∠ COD = 180° - ∠ AOC = 180° - 120° = 60°

Answer 2

Angle BOC is 80 degrees

Angle COD is 60 degrees