Explanation:
- m <a+m <b+m <c=180 {sum of angles in a straight line are 180}
- 3x+5+5x-18+7x-2=180
- 15x-15=180
- 15x=180-15
- 15x=165
- x=165/15
- x=11
- so, m<a=3x+5=3×11+5=33+5=38
m<b=5x-18=5×11-18=55-18=37
m <c=7x-2=7×11-2=77-2=75
part B: no bcuz their sum isn't 90 whereas to be complement it must be 90