Given that a || b, m∠2 = 63° and m∠9 = 105°.
Now, all the angles are as follows:
m∠5=
m∠2 = 63° [vertically opposite angle]
m∠7=
m∠9=105° [vertically opposite angle]
m∠8=
180°-m∠9=180°-105°=75° [Supplementry angles, m∠8+m∠9=180°]
m∠10=
m∠8=
180° [vertically opposite angle]
m∠6=
m∠8=75° [ Alternate angles]
m∠3=
m∠6=75° [vertically opposite angle]
m∠1=
180°-(m∠2+m∠3)=180°-(63°+75°)=42° [as m∠1+m∠2+m∠3=180°]
m∠4=
m∠1=42° [vertically opposite angle]
m∠11=m∠4=42° [ Alternate angles]
m∠13=
m∠11=42° [vertically opposite angle]
m∠12=
180°-m∠11=180°-42°=138° [as m∠8+m∠9=180°]
m∠14 =
m∠12=138° [vertically opposite angle]