A tent consists of frustum of a cone surmounted by a cone. If the diameters of the upper and lower circular ends of the frustrum be 14m and 26m respectively, the height of the frustum be 8m and the slant height of the surmounted conical portion be 12m, find the area of canvas required to make the tent. (Assume that the radii of the upper circular end of the frustum and the base of surmounted conical portion are equal)