Find $∠ADC$ given $A,D$ on circle with diameter $BC$ and $∠BAO = 50°$

Hints

Mark the congruent line segments in the figure (a circle has a constant radius) to observe that:

$$\measuredangle ABC = \measuredangle BAO$$

Then, try to use the fact that the measures of the angles in the same segment of a circle are equal (the measures of two angles at the circumference subtended by the same arc are equal):

$$\measuredangle ABC = \measuredangle ADC$$

Tags:

Geometry

Euclidean Geometry

Circles

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