Multiple choice general knowledge How big was Tyrannosaurus Rex's longest tooth? The same size as human teeth. About the size of a human hand. The size of a mini-van. As long as an elephant tusk. Reveal answer Fill a bubble to check yourself B Correct answer Explanation T-Rex had massive teeth that could grow up to 12 inches (30 cm) long, which is roughly the size of an adult human hand. These teeth were thick, conical, and designed for crushing bone rather than just slicing meat.