Find the values of a, b, c, and x.

The triangle has two interior angles given as $70^\circ$ and $70^\circ$. The third interior angle can be found using the angle sum property of a triangle.
Third interior angle $= 180^\circ - 70^\circ - 70^\circ = 180^\circ - 140^\circ = 40^\circ$.

The exterior angle $a$ is adjacent to one of the $70^\circ$ interior angles, forming a linear pair.

Alternatively, the exterior angle is equal to the sum of the two opposite interior angles:

The value of $a$ is $\boxed{\text{110}^\circ}$.

The triangle has two interior angles given as $60^\circ$ and $60^\circ$. The third interior angle can be found using the angle sum property of a triangle.
Third interior angle $= 180^\circ - 60^\circ - 60^\circ = 180^\circ - 120^\circ = 60^\circ$.
This means it is an equilateral triangle.

The exterior angle $b$ is adjacent to one of the $60^\circ$ interior angles, forming a linear pair.

Alternatively, the exterior angle is equal to the sum of the two opposite interior angles:

The value of $b$ is $\boxed{\text{120}^\circ}$.

The exterior angle given is $105^\circ$, and it forms a linear pair with the interior angle $C$.

We can verify this using the angle sum property of the triangle. The other two interior angles are $30^\circ$ and $75^\circ$.

This confirms the value of $C$.

The value of $C$ is $\boxed{\text{75}^\circ}$.