Q. In the diagram below of circle O, chords AB and CD intersect at E.If m∠AEC=34 and \mathrm{m} \overparen{A C}=50 , what is \mathrm{m} \overparen{D B} ?
Vertical Angles Congruence: Since AE and CD intersect at E inside the circle, angles ∠AEC and ∠DEB are vertical angles and therefore congruent.m/∠DEB=m/∠AEC=34∘.
Sum of Angles in Same Segment: The angles AEC and ACB are part of the same segment, so their measures add up to mAC◯.∠ACB=mAC◯−∠AEC=50∘−34∘=16∘.
Inscribed Angle Property: The angle ACB is inscribed in the arc ABC, so the measure of arc ABC is twice the measure of angle ACB. mAB◯=2×m∠ACB=2×16∘=32∘.
Rest of the Circle: The full circle is 360 degrees, so the measure of arc DB is the rest of the circle minus arc ABC.mDB◯=360 degrees −mAB◯=360 degrees −32 degrees =328 degrees.
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