What is Trigonometry?
April 12, 2026 • 11 min read • Math
Trigonometry studies relationships between angles and sides of triangles. This guide explains sine, cosine, tangent, the unit circle, and applications in physics, engineering, and navigation.
SOH-CAH-TOA
Sin = Opposite ÷ Hypotenuse
Cos = Adjacent ÷ Hypotenuse
Tan = Opposite ÷ Adjacent
The Unit Circle
The unit circle has radius 1 centered at (0,0). Points on the circle correspond to (cos θ, sin θ). This connects trigonometry to circular functions and extends beyond right triangles.
Applications
Trigonometry is essential in physics (waves, forces), engineering (structures, circuits), navigation (GPS, triangulation), and computer graphics (3D modeling, animations).