Answer:
vertex angle = 180° - 2x
Step-by-step explanation:
Since, the measure of each base angle of an isosceles triangle is represented by x.
So, by interior angle sum postulate of a triangle, we have:
x + x + vertex angle = 180°
2x + vertex angle = 180°
vertex angle = 180° - 2x
So, the vertex angle is represented by (180° - 2x).
