Explain why data from at least three seismic stations are needed to locate an earthquake epicenter

Each station has a circle made of possible epicenters. When you have atleast 3 epicenters you can narrow it down to 1 epicenter and there's that final point. Each station can detect how far away the epicenter was (by transverve body waves). When you only have one seismic station it's impossible to locate an earthquake epicenter.

This is what a calorimeter is used for simpler ex, to measure calories in food.