Graphic Design & Printing TechnologyCONIC SECTIONS
Conic section are the curves obtained by the intersection of a right circular
cone by a plane at different angles. Ellipse, parabola, and hyperbola are the
curves thus obtained and hence are called the conic sections or conics.
Draw an ellipse of major axis 80 mm and minor axis 50mm in concentric
circles method
l) Draw AB (80mm) and CD (50mm) the major and minor axes perpendicu-
lar to each other cutting at O.
With O as centre, draw two concentric circles of diameter 80 mm and
50mm as shown
Draw radial lines OE’,E, OF’, F etc. at convenient angular intervals of
say 30°.
From points E, F etc. on the major axis circle, draw lines perpendicular
to the major axis AB. From points El FI etc. on the minor axis circle,
draw lines parallel to the major axis. The intersect is of perpendicular and
parallel lines from points on the same radial line will fix a point on the
required ellipse.
(5) Draw a graceful curve through these points to define the ellipse.
Draw an ellipse of major axis 70mm and minor axis 45mm in concentric circle
method.