Answer:
The vertex angle is 94 degrees
Step-by-step explanation:
Let the vertex angle be x
Mathematically, the base angles of an isosceles triangle are the same
So if one of the base angles is 43 degrees, then the other base angle would be 43 degrees too
Mathematically, the sum of angles in a triangle is 180 degrees
Thus;
43 + 43 + x = 180
x = 180-86
x = 94 degrees