80 degrees.
40
20 degrees and the two equal angles will be 80 degrees each
107 because the overall sum of exterior angles add up to 360
If your "53" is in degrees, then the vertex angle is 74 degrees.
It is an isosceles triangle
40
135 degrees.
63
(180 - 38)/2 = 71 degrees (base angles of an isosceles triangle are congruent).
In any triangle exterior angle plus interior angles = 180 degrees
An Isosceles Triangle
20 degrees
yes
57.5 degrees
exterior angle theorem
105 degrees
84 degrees