1. **Problem statement:** In trapezoid PQST, UR is the midsegment. Given bases PQ = 11 and TS = 18, find the length of UR. 2. **Formula for midsegment of trapezoid:** The midsegment length is the average of the lengths of the two bases: $$UR = \frac{PQ + TS}{2}$$ 3. **Substitute the given values:** $$UR = \frac{11 + 18}{2}$$ 4. **Calculate the sum:** $$UR = \frac{29}{2}$$ 5. **Simplify the fraction:** $$UR = 14.5$$ 6. **Answer:** The length of midsegment UR is 14.5.