Area question

[swither]

I have 4 radio transmitters, each in a different corner of a square with 10 km long sides. Each radio has a range of 10 km. I need to calculate the area where you are in range of all four transmitters. Unfortunately i have no idea how to do this. Can anyone help me?

//Swither

[Muzza]

Det marks nar Matte D borjar ta slut... ;)

See this (http://www.maths.lth.se/query/answers/q200210.html#20021014220806) or this (http://www.maths.lth.se/query/answers/q9902.html#990211162036) for the solution.

[cyby]

! Is this an exam or something? :P Can't read Swedish myself...