Let C be a plane curve and P a point not on the plane of C. For simplicity (and in fact without loss of generality) we can take the plane containing C to be the xy-plane and put P on the positive Z-aXis, at say (0,0, h) with h > 0. Let r(t) = (x0), y(t)>; a S t S b be a parameterization for the curve C. We dene the ruled surface dened by C and P to be the surface formed by the collection of all lines joining the points of C to the point P. Denote by S = S (P, C) the portion of the ruled surface between the xy-plane and P. [This is sometimes referred to as a general cone.] a) Make a sketch of a surface S = S (P, C) , choosing any shape you like for the curve C