Khan Academy

Pythagorean theorem word problem: fishing boat (K-A)

Another Pythagorean theorem proof (K-A)

Bhaskara's proof of the Pythagorean theorem (K-A)

Garfield's proof of the Pythagorean theorem (K-A)

Pythagorean theorem proof using similarity (K-A)

Sine & cosine of complementary angles-video (K-A)

Trig word problem: complementary angles (K-A)

Using complementary angles (K-A)

Solving for a side in right triangles with trigonometry (K-A)

Solving for a side in right triangles with trigonometry-video (K-A)

Intro to inverse trig functions (K-A)

Laws of sines and cosines review (K-A)

Trig word problem: stars (K-A)

30-60-90 triangle example problem (K-A)

Area of a regular hexagon (K-A)

Special right triangles intro (part 1) (K-A)

Special right triangles intro (part 2) (K-A)

Special right triangles proof (part 1) (K-A)

Special right triangles proof (part 2) (K-A)

Special right triangles review (K-A)

Triangle similarity & the trigonometric ratios (K-A)

Trig challenge problem: trig values & side ratios (K-A)

Trig challenge problem: verify identities (K-A)

Rotating 2D shapes in 3D (K-A)

Slicing a rectangular pyramid (K-A)