silemus.

92Inscribed angle theorem

Points A, B and C lie on a circle with center O, and C is on the major arc AB. Angle AOB measures 110°. What is the measure, in degrees, of angle ACB? A) 35 B) 55 C) 110 D) 220

Angle ACB is 55°, since an inscribed angle is always half the central angle that opens onto the same arc. With angle AOB = 110°, angle ACB = 110/2 = 55°. The answer is B.

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