Pythagorean Theorem

Define Sine and Cosine

Note: The angles are in radians.

The Law of Sines

 sin(α)     sin(β)     sin(δ)
-------- = -------- = --------
   A          B          C

Use the Law of Sines to solve oblique (non-right) triangles.

Note: The angles are in radians.

Similar Triangles

The Law of Cosines

The Law of Cosines is used to find the remaining parts of an oblique (non-right) triangle when the lengths of two sides and the included angle is known (SAS), or the lengths of the three sides (SSS) are known.

Note: The angles are in radians.

For Python code to test arccos click HERE