Answer:
[tex]\angle m + \angle t + \angle n = 180[/tex]
Step-by-step explanation:
Required
Show that:
[tex]\angle m + \angle t + \angle n = 180^o[/tex]
To make the proof easier, I've added a screenshot of the triangle.
We make use of alternate angles to complete the proof.
In the attached triangle, the two angles beside [tex]\angle m[/tex] are alternate to [tex]\angle t[/tex] and [tex]\angle n[/tex]
i.e.
[tex]\angle 1 = \angle t[/tex]
[tex]\angle 2 = \angle n[/tex]
Using angle on a straight line theorem, we have:
[tex]\angle 1 + \angle m + \angle 2 = 180[/tex]
Substitute values for (1) and (2)
[tex]\angle t + \angle m + \angle n = 180[/tex]
Rewrite as:
[tex]\angle m + \angle t + \angle n = 180[/tex] -- proved