Given:
- Base of the isosceles triangle = 35

To find:
- Measure of the third side of the triangle

Explanation:
An isosceles triangle is a triangle that has two sides of equal length. In an isosceles triangle, the two equal sides are called legs, and the third side is called the base.

Step 1: Identify the information given:
- The base of the isosceles triangle is 35.

Step 2: Understand the properties of an isosceles triangle:
- In an isosceles triangle, the base angles are equal.
- The sum of the angles in a triangle is always 180 degrees.

Step 3: Determine the measure of the base angles:
- Since the base angles of an isosceles triangle are equal, we can divide the remaining degrees (180 - 35 = 145) equally between the two base angles.
- Each base angle would measure (145 / 2) = 72.5 degrees.

Step 4: Calculate the measure of the third side:
- The sum of all three angles in a triangle is 180 degrees.
- We already know the measure of the base angles (72.5 degrees each).
- To find the measure of the third angle, we subtract the sum of the base angles from 180 degrees.
- Third angle = 180 - (72.5 + 72.5) = 35 degrees.

Step 5: Conclusion:
- The measure of the third side of the isosceles triangle is 35 degrees.

Therefore, the measure of the third side of the isosceles triangle is 35 degrees.