Let's say and write the answers as quickly as possible.
a) If [tex]$x^{\circ}, y^{\circ},$[/tex] and [tex]$z^{\circ}$[/tex] are the angles of a triangle, then [tex]$x^{\circ} + y^{\circ} + z^{\circ} = \qquad$[/tex]
b) If [tex]$x^{\circ}, 110^{\circ},$[/tex] and [tex]$40^{\circ}$[/tex] are the angles of a triangle, then [tex]$x^{\circ} = \qquad$[/tex]
c) If [tex]$x^{\circ}$[/tex] is the exterior angle and [tex]$y^{\circ}$[/tex] and [tex]$z^{\circ}$[/tex] are the two opposite interior angles of a triangle, then [tex]$x^{\circ} = \qquad$[/tex]