Why is a minimum of three seismic stations needed to find the epicenter of an earthquake?

Answer 1

Since this is not my area of expertise, I searched Google under the key words "detect epicenter earthquake" to get these possible sources:

http://www.explorelearning.com/index.cfm?method=cResource.dspExpGuide&ResourceID=371
(Broken Link Removed)
http://servercc.oakton.edu/~billtong/eas100lab/lab10quake.htm

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.