SOLVE THIS ASAP and please show me the solving steps

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

x+2x+6x=180 degrees

Simplify: 9x=180 degrees

Divide both sides by 9

x= 20 degrees

Plug in:

x degrees = 20 degrees

2x degrees = 40 degrees

6x degrees = 120 degrees