Final answer:
Old Saint Peter's Basilica was the basilica that imposed a pattern on church buildings by Constantine in the 4th century CE.
Step-by-step explanation:
The basilica that imposed a pattern on church buildings by Constantine in the 4th century CE was Old Saint Peter's Basilica. This basilica was located in Rome and was built on the site where it was believed the apostle Peter had been buried. It followed the plan of the Roman basilica and added a transept to give the church a cruciform shape.