The Pythagorean theorem intro | Right triangles and trigonometry | Geometry | Khan Academy
9:36
Pythagorean theorem II | Right triangles and trigonometry | Geometry | Khan Academy
12:43
Trigonometry made easy
1:02:47
Calm Chopin | 15 Of The Most Relaxing Chopin Pieces
48:55
Pythagoras' theorem (a) | Math History | NJ Wildberger
41:56
Parallel and Perpendicular Lines, Transversals, Alternate Interior Angles, Alternate Exterior Angles
14:13
Introduction to ratios | Ratios, proportions, units, and rates | Pre-Algebra | Khan Academy
12:08
Part 2 of proof of Heron's formula | Perimeter, area, and volume | Geometry | Khan Academy
1:53:22