How to use this calculator
- Identify the measurements labelled Total surface area S, Base edge a. Check whether the figure satisfies the assumptions described below.
- Enter positive measurements in a common unit. Use the degree symbol convention for angles. Ratios such as eccentricity have no unit.
- Select Calculate. Inspect the result labels: lengths, areas and volumes have different dimensions. Copy the output or print the page if you need a record.
The formula
Total surface area S = 96; Base edge a = 6
Worked example
For Total surface area S = 96 cm², Base edge a = 6 cm, applying the displayed relationship gives base edge ≈ 6 cm. The remaining related measurements appear in the result panel. The example uses ideal dimensions and rounds only for display.
Model and limitations
The vertical height, face slant height and lateral edge are different lengths. A face slant height runs from the apex to the midpoint of a base edge. Total surface area is the base plus the four triangular faces.
Do not substitute a lateral edge for a face slant height. The apex must lie over the base centre for these calculators. Inputs are limited to 10⁹ for lengths, 10¹⁸ for areas and 10²⁷ for volumes. Extremely thin or nearly degenerate figures may lose numerical accuracy; avoid treating displayed rounding as a measurement tolerance.