Answer:
a. 84°
Step-by-step explanation:
The measurement of vertex angle of an isosceles triangle if one of the base angle measures is 48 degrees than the vertex angle should be 84 degrees.
So in the following question let us suppose the vertex angle to be called as ‘x’, so according to the equation 48 degrees + 48 degrees + x equals to be hundred and eighty degrees, and next adding two numbers would give, x+96=180, hence the final result of the vertex angle would be 84 degrees.