Tangency
Introduction
Tangent lines, arcs, circles, or surfaces are lines, arcs, circles, or surfaces
that touch but do not intersect. When drawing irregular or noncircular
curves with french curves, you plot a series of tangent arcs. When you
indicate round corners on an otherwise straight plane, you are working with
an arc that is tangent to two lines at right angles. Make sure all points of
tangency are clearly defined before you begin inking.
To draw a
circle tangent
To draw a circle tangent to a line at a given point, follow this table:
to a line
Step
Action
1
Given line AB with point P representing the point of tangency,
erect a perpendicular.
2
Set off the length of the radius of the required circle as a point on
the perpendicular and mark it C.
3
Draw the circle using C as the center point and CP as the radius.
Figure 2-26 shows how to draw a circle tangent to a line.
Figure 2-26.—A circle
tangent to a line.
Continued on next page
2-27
