Answer: 11 units
Explanation:
We can say that
by AA Similarity Postulate. This is since
and both ∠TSQ and ∠RSP are right angles, making them congruent.
Similar triangles have a property that corresponding sides are proportional. Hence, we can say that
![(ST)/(PS)=(SQ)/(SR)\\(15)/(PS)=(9)/(12)\\(15)/(PS)=(3)/(4)\\60=3*PS\\PS=20](https://img.qammunity.org/2023/formulas/mathematics/high-school/trlbzihity9cj253nvkspmt1dgkrw2jz6j.png)
We also know that PS is the combined length of PQ and QS. Since we know that QS is 9, let's substitute PQ + 9 in and solve.
![PQ+9=20\\PQ=11](https://img.qammunity.org/2023/formulas/mathematics/high-school/8aqgw814xmtrggb0ymazxhsc4ktaksxh8b.png)