Answer:
43°
Step-by-step explanation:
(x + 53)° + (x + 74)° + 73° = 180°
(x + 53 + x + 74)° = 180° - 73°
(2x + 127)° = 107°
2x + 127 = 107
2x = 107 - 127
2x = - 20
x = - 20/2
x = - 10

The answer is for that problem is -3
Triangle ABC is congruent to triangle MNC by SSS, AAA or AA .....!!