Explaining the trigonometric ratios of right triangles for sine, cosine, and tangent

Finding the six trigonometric ratios for a right triangle

Using trig to find the length of the side of a right triangle given an angle and side length

Using trig to find an angle in a right triangle with two given sides

Using the Pythagorean Trig Identity to derive the secondary Pythagorean Identities

Using the double angle identities for cosein to derive the half-angle identities for sine and cosine

Using the Reciprocal, Ratio, and Pythagorean Identities to verify a trig identity

Proving a trig identity involving sine, cosine, and cotangent