1. **State the problem:** We have a triangle with three angles: 38°, $u + 43°$, and 46°. We need to find the value of $u$. 2. **Recall the triangle angle sum rule:** The sum of the interior angles of any triangle is always 180°. So, $$38 + (u + 43) + 46 = 180$$ 3. **Set up the equation:** $$38 + u + 43 + 46 = 180$$ 4. **Combine like terms:** $$38 + 43 + 46 = 127$$ So, $$127 + u = 180$$ 5. **Solve for $u$:** $$u = 180 - 127 = 53$$ 6. **Answer:** The value of $u$ is 53°.