Answer:
67⁰
Explanation:
According to the Triangle Sum Theorem, all three angles sum up to 180⁰.
<A + <B + <C = 180⁰
You are given the two angles. To find the third or the missing angle you will use the triangle sum thereom.
<A + <B + <C = 180⁰
90⁰ + 23⁰ + <C = 180⁰
113⁰ + <C = 180⁰
113⁰ - 113⁰ + <C = 180⁰ - 113⁰
<C = 67⁰
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