1. **State the problem:** We are given a triangle with angles 68°, 78°, and $x$° and need to find the value of $x$. 2. **Recall the triangle angle sum rule:** The sum of the interior angles of any triangle is always 180°. This means: $$68^\circ + 78^\circ + x^\circ = 180^\circ$$ 3. **Set up the equation:** $$68 + 78 + x = 180$$ 4. **Add the known angles:** $$146 + x = 180$$ 5. **Isolate $x$ by subtracting 146 from both sides:** $$\cancel{146} + x = 180 - \cancel{146}$$ $$x = 34$$ 6. **Final answer:** The value of $x$ is **34°**.