1. **State the problem:** We are given two adjacent angles around a point, one is 70° and the other is $y$. We need to find the value of $y$. 2. **Use the fact that angles around a point sum to 360°:** The sum of all angles around a point is 360°. Since the two angles are adjacent and form a straight line around the point, their sum is 360°. 3. **Set up the equation:** $$70 + y = 360$$ 4. **Solve for $y$:** $$y = 360 - 70$$ $$y = 290$$ 5. **Reason:** The reason for this is that angles around a point always add up to 360°, so the unknown angle $y$ must be the difference between 360° and the known angle 70°. **Final answer:** $$y = 290$$