Examples
Examples
Try the starting example
- Tarp width across symmetric ridge (m)
- 6
- Tarp length along ridge (m)
- 4
- Ridge height above ground (m)
- 2
- Each side angle down from horizontal (degrees)
- 30
- Horizontal covered width (m)
- 5.196152
- Projected rectangular ground area (m²)
- 20.78461
- Lower tarp-edge height (m)
- 0.5
- Fabric length on each side (m)
- 3
Try another scenario
- Tarp width across symmetric ridge (m)
- 6
- Tarp length along ridge (m)
- 4
- Ridge height above ground (m)
- 2
- Each side angle down from horizontal (degrees)
- 0
- Horizontal covered width (m)
- 6
- Projected rectangular ground area (m²)
- 24
- Lower tarp-edge height (m)
- 2
- Fabric length on each side (m)
- 3
Calculation method
Calculation method
Horizontal covered width (m)
Tarp cross-ridge width × cos(side angle).
Projected rectangular ground area (m²)
Projected covered width × ridge length.
Lower tarp-edge height (m)
Ridge height − half cross-ridge fabric width × sin(side angle).
Fabric length on each side (m)
Half cross-ridge fabric width.
Symbols and units
- a
- Tarp width across symmetric ridge (m)
- b
- Tarp length along ridge (m)
- c
- Ridge height above ground (m)
- d
- Each side angle down from horizontal (degrees)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- Ideal symmetric straight-sided A-frame tarp with no sag, end slope, overhang change or wind deformation. It is geometry only; coverage does not establish weatherproof shelter or structural safety.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
OpenStax: arithmetic and geometry ↗
Background reading; this does not imply endorsement or independent review of SumFizz.