Question

(question 31) if arc mBC =120 and arc mAD =50 whatis the measure of angle DYC

Answer 1

Answer:  D) 95

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Explanation:

First, let's calculate angle BYC. This is the angle formed by the chords that subtend the arcs mentioned. This angle faces or is aimed toward the direction of the arcs. To find this angle, we'll average the arc measures like so:

angle BYC = (arcAD + arcBC)/2

angle BYC = (50+120)/2

angle BYC = 170/2

angle BYC = 85 degrees

Then we'll use the idea that angles BYC and DYC are supplementary (aka they form a straight 180 degree angle)

angleBYC + angleDYC = 180

angleDYC = 180 - angleBYC

angleDYC = 180 - 85

angleDYC = 95 degrees

which is why the answer is choice D.