About GeometryFormula.com

GeometryFormula.com is a free, independent reference built by a digital publisher who makes education utilities. The goal is simple: the clearest, most trustworthy geometry formula reference on the web — one you can also drag, compute, and print.

How we verify the formulas

A math reference with a single wrong formula is worse than useless. So every formula on this site is defined once, in code, and checked by an automated test that evaluates it against known values — the 3-4-5 triangle, the unit circle, a cube of side 2, a cone with radius 3 and height 4, and dozens more. The same verified functions power the printed formula, the worked example, and the live explorer, so they can never drift apart. If a formula or a worked number were wrong, the build would fail before it ever reached you.

How the pages are written

Each page opens with a direct, quotable answer to its question, then gives the formula, a worked example with concrete numbers, and an interactive explorer. Variable names are consistent everywhere (see the glossary on the homepage). Exam preset pages link the official state reference sheets — NYSED, TEA, VDOE, and others — as primary sources.

What we don’t do

We don’t copy content or PDFs from other sites; every sheet we host is generated from our own verified data. There’s no account to create, nothing to pay for, and no advertising. And we keep the pages fast and printable, because a formula sheet is only useful if you can actually use it in class or on paper.

Privacy

We use Google Analytics to see which pages people actually find useful. It sets a first-party cookie and records page views and approximate location; we don’t sell or share that data, and we don’t use it to build advertising profiles. The explorers and the Sheet Builder run entirely in your browser: the formulas are computed locally and the printable sheets are generated on your own device, not on a server. Full details in our privacy policy.

Corrections

Found something that looks off? Because our formulas are test-covered we take accuracy seriously — corrections are always welcome and are fixed at the source.

Contact

Questions, corrections, embed requests, or feedback from teachers and students are all welcome. Email us at hello@geometryformula.com and we’ll get back to you.