Problem VIII. To draw the plan and elevation of an octahedron when
one diagonal is vertical and an edge parallel to the vertical plane
of projection; and a plan when one of the faces is horizontal
Problem IX. To draw the plan of a tetrahedron, when the inclina-
tions of a face and one edge of that face are given: also an eleva-
tion on a given vertical plane
Problem X. To draw the plan of a cube, when the inclination of a
face and the heights of two points in that face above the horizon-
tal plane of projection are given
Problem XI. To draw the projection of an octahedron when the inclina-
tions of two of its diagonals to the plane of projection are given
Problem XII. To draw the projection of a rectangular parallelopiped
when the distances from the plane of projection of three of its
angular points in the same face are given