function cosval(a, b, c) {
			return cossign(a, b, c) / dist(a, b) / dist(b, c);
		}
function cosval(a, b, c) {
			return cossign(a, b, c) / dist(a, b) / dist(b, c);
		}
function cosval ( a , b , c ) { return cossign ( a , b , c ) / dist ( a , b ) / dist ( b , c ) ; }
/* js/src/d2/irrational /* js/src/d2/irrational/cosval.js 
Typically this kind of computation is not allowed. Computing distances
between two vertices in the general case requires to compute the square root
of a number. We only work with rationals in our algorithms and cannot handle
irrationals that could appear when allowing the use of square roots.
/ * js / src / d2 / irrational / * js / src / d2 / irrational / cosval . js Typically this kind of computation is not allowed . Computing distances between two vertices in the general case requires to compute the square root of a number . We only work with rationals in our algorithms and cannot handle irrationals that could appear when allowing the use of square roots .