Homework completed

Ran into some trouble with the area and obtuse syntax. 
My original area function was: 

function triArea(A, B, C) {
  var area = ((A + B + C) * 0.5);
  return Math.sqrt(area(area - A)(area - B)(area - C));
}

which returned the type error: TypeError: number is not a function

That held me up for a bit. Otherwise... I'm actually pretty comfortable with javascript. Especially if I'm learning it while well rested.