Answer: 35°
Step-by-step explanation:
- Step #1: Write the 'triangle sum theorem' for the triangle which is:
m∠A + m∠B + m∠C = 180°
- Step #2: Substitute the given angle measures
40° + 105° + m∠C = 180°
m∠C + 145° = 180°
Subtract 145° from both sides.
m∠C = 35°
So, the measure of the missing angle (x) is 35°.
