you need
  • - paper;
  • - handle;
  • - tsirkl;
  • - line.
In answering this question, we first need to decide - what parameters specified section.
Let this be the line of intersection plane of the base of the cone l with the plane of the section and the point O, which is the crossroads of the height of the cone, with its cross-section.

Figure 1 illustrates the construction.The first step of the construction section - is drawn through the center section of its diameter, extended to l perpendicular to this line.The result is a point of L. Further through point O draw a straight LW, and build two guide cone, lying on the main section O2M and o2c.At the intersection of these guides are the point Q, and also have shown a point W. This first two points of the desired section.
How to build a section of the cone
Now hold the base of t
he cone diameter BB1 perpendicular MS and build a cross-section perpendicularly O2V and O2V1.In this section through point O draw a straight RG, parallel BB1.T.R and t.G - two more points of the desired section.If the cross sectional outline ball is known, then it can be built at this stage.However, this is not an ellipse, but something elliptical, having a symmetry with respect to the segment QW.Therefore, you should build as much as possible points section to connect them to further smooth curve to obtain the most reliable sketch.
Build an arbitrary point of the intersection.To do this, perform the base of the cone of arbitrary diameter AN and build the appropriate guides and O2A O2N.Through point O draw a line passing through the PQ and the WG, to its intersection with the newly built rails at points P, and E. This is two points of the desired section.Continuing in the same way and on, you can dial any number of desired points.
However, the procedure for obtaining them can be a bit easier using symmetry with respect to QW.This can be done in the desired sectional plane carry out direct SS ', RG parallel to their intersection with the surface of the cone.Construction is completed rounding built a broken chord.It is enough to build half of the desired cross-section due to the already mentioned symmetry with respect to QW.