Elliptical, oval and rectangular tube development
The straight tube of elliptical, flat-oval (obround) or rectangular section, and the rectangular tube cut at an angle. The plate is a rectangle whose length is the section perimeter on the neutral axis.
Elliptical Tube
A shell of elliptical section. The pattern is rectangular, but its length is the perimeter of the ellipse — no closed form, so it is integrated.
Oval Tube
The obround tube: two semicircles joined by two straight runs. The easiest shape to form after the circle — only two radii, and they are equal.
Truncated Rectangular Tube
Rectangular duct ending on a tilted plane — a roof, a sloping wall. The mouth becomes four runs: straight on two faces, sloping on the two sides.