Ugh, more algebra pretending to be geometry. Why?
This is a pretty awful instance of the genre, with no units on the constant 16, assumed to be degrees.
The total arc measure in a circle is 360 degrees. Geometry part over.
3m + 16 + 2m + 3m = 360
8m = 344
m = 344/8 = 43
Arc measures:
Arc 3m+16 = 3(43)+16 = 145°. The angle subtended by that arc is half that, 145/2=72.5°
Arc 2m=2(43)=86°. The angle subtended is half that, 43°
Arc 3m=3(43)=129°. The angle subtended is half that, 64.5°