Answer:
(a) 46°
(b) 86°
Step-by-step explanation:
When the secants cross externally (figure a), the angle where they cross is half the difference of the subtended arcs.
When they cross internally (figure b), the angle is half the sum of the subtended arcs.
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<h3>(a)</h3>
Half the difference of arcs VW and VX is ...
∠VYW = 1/2(160° -68°) = 46°
m∠VYW = 46°
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<h3>(b)</h3>
Half the sum of arcs AB and CD is ...
∠CED = 1/2(arc AB +arc CD)
2×∠CED = arc AB +arc CD . . . . . multiply by 2
2×∠CED -arc AB = arc CD . . . . . subtract arc AB
arc CD = 2×85° -84° = 86°
m arc CD = 86°
