R/triangle.area.R

In egg: Distances and areas on the surface of an egg

triangle.area = function(v1, v2, v3) {
  # Find the area of the triangle defined by the vertices v1, v2 and v3
  a = magnitude(v1 - v2)
  b = magnitude(v1 - v3)
  c = magnitude(v2 - v3)
  s = (a + b + c)/2
  return (sqrt(s*(s - a)*(s - b)*(s - c)))
}