a)
x= 180 - 112
x= 68°
b)
x= 180 - ( 50 + 90)
x= 40°
c)
y= 115° ( because virtually opposite angles are equal. )
x= 360 - ( 115 + 115 ) (270/2)
x= 65°
d)
y= 180 - ( 59 + 64 )
y= 57°
x= 59°
e)
y= 180 - ( 47 + 90)
y= 43°
z= 180 - 47
z= 133°
x= 180 - ( 43(y) + 90 )
x= 47°
f)
x= 90 - 19
x= 71°