Answer:
9.110° and y are the same(alternate angles)
thus y=110°. 110+x=180(seplementary angles). thus x=180-110=70°
z(alternate)=70°
10.y=78°. x=(180-78)=102°. z=102°
11.x=83°. y=(180-83)=97°. z=97°
12.y=37°. x=(180-37)=143. z=143°
to confirm the answers all angles in a circle at the centre add up to 360°
