Figure 14-55.--Development of a rectangular transition piece, which is not a true pyramid.
3. Draw the surface pattern by constructing one
this is by drawing diagonals that split the sides into two
triangle at a time (view C).
triangles. These diagonals are usually drawn as dotted
lines to separate them from other elements. Then, the
The fitting in figure 14-56 has a warped surface. Its
true length of each element is found, and the surface
base is round and its top is oblong. The following
pattern developed by constructing each triangle in turn.
method for development consists of dividing the
To find the true-length lines, draw a true-length
surface into quadrilaterals of about the same size. A
diagram.
quadrilateral is a plane figure having four sides and four
angles. A diagonal is then drawn across each of these
1. Draw the orthographic views with the bend lines
to produce two triangles. When the true lengths of these
and the diagonals (view A).
elements have been found, the surface pattern may be
2. Draw a true-length diagram of these elements
drawn triangle by triangle.
(view B).
14-35