Final answer:
Each base angle of an isosceles triangle with a vertex angle of 70 degrees is 55 degrees, which is not listed among the provided options.
Step-by-step explanation:
If an isosceles triangle has a vertex angle of 70 degrees, then each base angle must be calculated to find their measures. In an isosceles triangle, the two base angles are equal. Since the sum of all angles in any triangle is always 180 degrees, we can find the measure of each base angle by subtracting the vertex angle from 180 degrees and then dividing the result by 2.
Each base angle of an isosceles triangle with a vertex angle of 70 degrees is 55 degrees, which is not listed among the provided options. Let's perform the calculations: 180 degrees - 70 degrees = 110 degrees. Now divide 110 degrees by 2 to find each base angle: 110 degrees / 2 = 55 degrees. Therefore, each base angle is 55 degrees.
Thus, the correct answer is not listed among the options provided but would theoretically be 'E) 55 degrees' if such an option existed.