Answer:
part A:
If ABC is a triangle then,
2x+4+2x-9+x=180degree
or, 5x-5=180degree
or, 5x=(180+5)degree
or, 5x= 185degree
or, x=185÷5 = 37degree ans.
PartB
now put the value of x in angle A
i.e angle A = 2x-9
or, angle A= (2×37) - 9
or, angle A= 74 - 9
therefore, angle A= 65degree ans.
