Answer
1. The hypotenuse of the triangle UR is a part of is US.
2. The hypotenuse is always longer than the other sides.
3. US is longer than UR.
4. The hypotenuse of the triangle US is a part of is TS.
5. From (2), it follows that TS is longer than US.
6. Since TS is longer than US and US is longer than UR, TS is longer than UR.