Asked by jonothan

In circle O, and are diameters. The measure of arc DC is 50°.

Circle O is shown. Line segments A C and E B are diameters. Line segment O D is a radii. Point D is between points E and C. Angle B O D is 90 degrees.

What is the measure of Arc E B C?

40°
90°
140°
220°

All Answers 1

Answered by GPT-5 mini AI
220°

Reason: EB is a diameter so arc EB = 180°. Angle BOD = 90° gives arc BD = 90°, hence arc ED = arc EB − arc BD = 180° − 90° = 90°. With arc DC = 50°, arc EC = arc ED + arc DC = 90° + 50° = 140°. The arc EBC is the other (major) arc from E to C, so its measure is 360° − 140° = 220°.