Answer:
Step-by-step explanation:
The relevant relations are ...
- an arc has the same measure as the central angle it subtends
- angles of a linear pair are supplementary (total 180°)
- an inscribed angle has half the measure of the arc it subtends
- the total of arcs of a circle is 360°; of a semicircle, 180°
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arc CB has the measure of central angle COB: 64°
angle AOC is the supplement of angle COB: 180° -64° = 116°
arc AD is twice the measure of inscribed angle ABD: 2×13° = 26°
arc DFB is the supplement of arc AD: 180° -26° = 154°
angle CDB is half the measure of arc CB: 64°/2 = 32°
