1. **State the problem:** We need to find the exterior angles $a$, $b$, and $c$ of a triangle where the interior angles adjacent to $c$ and $b$ are $70^\circ$ and $67^\circ$ respectively. 2. **Recall the exterior angle rule:** An exterior angle and its adjacent interior angle form a straight line, so their measures add up to $180^\circ$. 3. **Calculate each exterior angle:** - For angle $c$: $$c = 180^\circ - 70^\circ = 110^\circ$$ - For angle $b$: $$b = 180^\circ - 67^\circ = 113^\circ$$ 4. **Find angle $a$:** The sum of interior angles in a triangle is $180^\circ$. Let the interior angle adjacent to $a$ be $x$. Then: $$70^\circ + 67^\circ + x = 180^\circ$$ $$x = 180^\circ - 70^\circ - 67^\circ = 43^\circ$$ Since $a$ is the exterior angle adjacent to $x$: $$a = 180^\circ - 43^\circ = 137^\circ$$ 5. **Final answers:** $$a = 137^\circ, \quad b = 113^\circ, \quad c = 110^\circ$$