Khan Academy

Pythagorean theorem proof using similarity (K-A)

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

Geometry word problem: a perfect pool shot (K-A)

Geometry word problem: Earth & Moon radii (K-A)

Geometry word problem: the golden ratio (K-A)

Challenging similarity problem (K-A)

Using similar & congruent triangles (K-A)

Solving similar triangles. (K-A)

Solving similar triangles: same side plays different roles (K-A)

Area of triangle formula derivation (K-A)

Area of triangle from coordinates example (K-A)

Distance formula. (K-A)

Finding distance with Pythagorean theorem (K-A)

Dividing line segments (K-A)

Dividing line segments: graphical (K-A)

Midpoint formula. (K-A)

Area of trapezoid on the coordinate plane (K-A)

Challenge problem: Points on two circles (K-A)

Classifying quadrilaterals on the coordinate plane (K-A)

Coordinate plane word problem (K-A)

Points inside/outside/on a circle (K-A)

Ratio in which a line divides a line segment (K-A)

Ratio in which a point divides a line segment (K-A)

Intro to the trigonometric ratios (K-A)

Trigonometric ratios in right triangles (K-A)