Polygon Rafter Calculator

Strong Built Establishments Builders

SBE Builders is a commercial and residential framing contractor located in Discovery Bay California. Our Systematic Construction Logic produces Strong Built Establishments.

All online tools use javascript to calculate the dimensions. Use at your own risk. If the answers look wrong then verify the answers with a calculator.

This polygon rafter script - calculator will return the polygon rafter geometry angles and trigonometry rafter measurements for equal sided polygon roof framing.

In a circle of radius r, the length of the chord that subtends a central angle x is r * sin( x/2).
This script uses the theory of an polygon inscribed inside of a circle. So the radius is the run of the polygon hips and the chord is the length of the sides of the polygon.

polygon-rafter.dxf -- auto generated DXF CAD file of polygon rafters drawing each time script is run
polygon-rafter.pl source code for perl script that generates these octagon rafter calculations
dxf_header.txt DXF header text file used by this script

SBE Builders
5305 Laguna Ct.
Discovery Bay, California 94505
(925) 634-6022 • Fax: (925) 634-6022

Commercial & Residential Framing Contractor
Buil it Green Framing Contractor
Licensed Building Contractor
CA LIC.# 546126

Systematic Construction Logic

Awareness: Be aware of all new building materials and codes that effect the entire structure.
Understanding: Have a complete understanding of the construction sequences that effect the entire structure.
Optimizations: Pursue ideas that optimize the construction sequences that effect the entire structure.

Geometric Development of Tetrahedron
using a Steel Framing Square