Answer:
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Sum of exterior angles measures is 360°.
Set up the following equation and solve for x:
- 9x + 1 + 5x + 12 + 10x - 37 = 360
- 24x - 24 = 360
- 24x = 384
- x = 384/24
- x = 16
Find exterior angle measure at vertex C:
- 10*16 - 37 = 160 - 37 = 123°
We know interior and exterior angles on the same vertex form a linear pair.
Find interior angle at vertex C, the ∠BCA:
- m∠BCA = 180° - 123° = 57°