Given,
y = 5x
According to the angle sum property of a triangle,
60° + x + y = 180°
60° + x + 5x = 180°
60° + 6x = 180°
6x = 180° - 60° = 120°
x = 120°/6 = 20°
y = 5x = 5 x 20 = 100°
According to the exterior angle property,
z = 60° + y
= 60° + 100°
= 160°
