shrinkDimensions.js

var shrinkDimensions = function(a, b, m) {
    if (a * b > m) {
        var k = a/b; // a = bk , b = a/k
        var A, B;
        // let ab = m
        // b^2 * k = m
        // b^2 = m/k
        B = Math.sqrt(m/k);
        // a = bk
        A = B * k;
        return [A, B];
    } else {
        return [a, b];
    }
};