See Regular Tetrahedron 1234.

Construct an equilateral triangle such that its vertices and circumcentre are (in any order) 1,2,3, and 4 units from the origin.

What is the length of a side of the triangle?

Solution now added.

Edited on April 6, 2012, 12:49 am

Posted by broll on 2012-03-30 23:43:04