Law of Cosines Visualization

Interactive visualization of the Law of Cosines with draggable triangle and step-by-step proof

Law of Cosines

c² = a² + b² - 2ab·cos(C)

Side Lengths

a = 0
b = 0
c = 0

Angles

∠A =
∠B =
∠C =
Triangle Type: Acute

Verification

Derivation from Pythagorean Theorem

Step {current} of {total}

Example Triangles

Acute Triangle

All angles < 90°

Right Triangle

One angle = 90°

Obtuse Triangle

One angle > 90°

SAS Case

Given two sides and included angle

SSS Case

Given three sides

Practice Problems

History