Figure 5-26.-Use of an auxiliary section.Figure 5-27.-A. Multi-view view of block in normalposition; B. Multi-view view of block revolved 30 degreeson axis perpendicular to vertical plane.regular planes of projection. An auxiliary viewis one that is projected on a plane other than oneof the regular planes.A rectangular object is in normal positionfor regular multi-view orthographic projectionwhen each of its faces is parallel to one regularplane of projection and perpendicular to the othertwo. This is the case with the object shown infigure 5-27, view A.USE OF REVOLUTIONS.— In a REVOLU-TION, the object is projected on one or more ofthe regular planes of projection. However, insteadof being placed in normal position, the object isrevolved on an axis perpendicular to one of theregular planes.Figure 5-27, view B, is a three-view multi-viewprojection showing the block in 5-27, view A, asit would appear if it were revolved 30 degrees onan axis perpendicular to the profile plane ofprojection. Figure 5-28, view A, shows how theFigure 5-28.-Use of revolution on axis perpendicular to(A) horizontal plane and (B) vertical plane.5-17