It is 120 because you have to divide 210 by 7 which is 30 then multiply by 4 so 30 x 4 = 120.
Part A: B)35
As the angle y° equals to angle 2x°, y=2x.
And the sum of the angle (x+y+5°)and the angle 2x° is 180°.Therefore,
x+y+5°+2x =180°
x+2x+5°+2x=180°
5x+5° =180°
5x =175°
x =35°
Part B: C)110°
As I said, y =2x
And the unlabled angle eaquals to the angle(x+y+5°).
Therefore,
the unabled angle= x+y+5°
=x+2x+5°
=3x+5°
=3(35°)+5°
=110°