Point O is the center of the circle in the diagram. What is
m∠BCA?
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we know that
The measure of the external angle is the semidifference of the arcs that it covers.
so
[tex] m\ angle\ BCA= \frac{1}{2} *(arc\ BOA-arc\ BA)\\\\ m\ angle\ BCA= \frac{1}{2} *(250-110)\\ \\ m\ angle\ BCA=70\ degrees [/tex]
therefore
the answer is
The measure of angle BCA is equal to [tex] 70\ degrees [/tex]