1. The problem states that there are 2 angles labeled as $a$ and the exterior angle is 35 degrees. 2. Recall the exterior angle theorem: The exterior angle of a triangle is equal to the sum of the two opposite interior angles. 3. Let the two interior angles be $a$ and $a$, so the exterior angle $= 35$ degrees. 4. According to the theorem, $$35 = a + a = 2a$$ 5. Solve for $a$: $$a = \frac{35}{2} = 17.5$$ 6. Therefore, each interior angle $a$ is 17.5 degrees.