Law of cosines

Client

c² = a² + b² − 2ab cos(C)—enter sides a, b and angle C in degrees.

About Law of cosines

Find side c from sides a, b and included angle C (degrees). The interactive transform on this page runs in your browser tab—Toolcore does not need your paste for the core operation described above.

How to use this page

Paste or type in the main workspace, run the primary action from the toolbar, then copy or download the result. Use Load example when the page offers it, or URL prefill (?q= / ?qb=) so agents and tickets open the same input.

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Nearby workflows on Toolcore

  • Law of sines — Find side b from angle A (°), side a, and angle B (°). when units or numeric output should be checked on a related calculator.
  • Heron triangle area — Triangle area from three side lengths via Heron's formula. when units or numeric output should be checked on a related calculator.
  • Trigonometry calculator (degrees) — sin, cos, and tan of an angle in degrees—local double-precision trig. when units or numeric output should be checked on a related calculator.
  • Math expression evaluator — Evaluate basic + − × ÷ arithmetic with parentheses in your browser—no variables. when units or numeric output should be checked on a related calculator.

Common use cases

  • Law of cosines — third side for quick local checks without uploading data.
  • Copy results into tickets, docs, or classroom notes.

Common mistakes to avoid

  • Unexpected input shape

    See the intro and how-to notes for accepted formats.

FAQ

Is processing local?

Yes—this runs entirely in your browser.

Agent prefill?

Open the page directly—multi-field inputs are not URL-prefilled.

More tools

Related utilities you can open in another tab—mostly client-side.