SOLVE THIS ASAP and please show me the solving steps

Answer:
45.2°
Step-by-step explanation:
a = 14
b = 11
c = 10
The Law of Cosines is given as:
arccos (a²+b²﹣c²/2ab)
In this above question, to find m
= arccos(11²+14²﹣10²/2·11·14)
= 45.20717°
Approximately = 45.2°
Option d is the correct answer