Axis perpendicular to the vertical plane - tetrahedron:

A tetrahedron of side 60 millimeter has its base parallel to the VP, along with an edge of the base inclined at 45^o to the HP. However the corner contained via such edge is on the HP. Sketch its projections.

Solution

 Construction procedure is given as:

(a) Sketch a line at 45o to xy in VP, and complete the elevation a′ b′ c′ or along with point c′ in xy Mark centre ′.

(b) Sketch line abc parallel to xy representing the base in elevation.

(c) For mark point O in plan, rotate o′ a′ in elevation to o′ to o′a′1 parallel to xy.

(d) Situate a¹ along extension line of abc and mark o as or a¹ o equal to 60 millimeter along axis.

(e) Connect oa₁, ob₁, oc₁ is like dotted line to finish the plan.