What are the strengths of the t-rex?

Why is T-rex called King of Dinosaurs? Well T-rex is called that because of 2 reasons. Reason1- When T-rex was discovered it was the largest predatory dinosaur ever found. But later after that gigantosaurus was found. {which leads into Reason2} Reason 2- Some people wanted gigantosaurus to be king of dinosaurs;but many scientists debated who would win in a battle. And the facts pointed to t-rex wining. So t-rex has remained King of Dinosaurs!