I don't know what you mean by area since it's just a spiral going up the z axis, but x goes from -3 to +3 and so does y. So it's circular with a radius of 3 so the "area" if you look at it top down, along the z axis, is pi*3^2 = 28.2743338823081.
To get the pitch, first get the period. x gets back to the same x after t = 1, 2, 3, 4, etc. - basically integers because that is when 2*pi*t is a multiple of 2*pi. So when t = 1,2,3,4 then z will equal 2,4,6,8,.... So the period is 2 units of z which means the pitch is 1/2 unit of z^(-1).
