Trigonometry (from Ancient Greek τρίγωνον (trígōnon) 'triangle' and μέτρον (métron) 'measure') [1] is a branch of mathematics concerned with relationships between angles and side lengths of triangles.
Trigonometry helps us find angles and distances, is used a lot in science, engineering, video games, and more! The triangle of most interest is the right-angled triangle. The right angle is shown by the little box in the corner: Another angle is often labeled θ, and the three sides are then called: Why a Right-Angled Triangle?
Trigonometry, the branch of mathematics concerned with specific functions of angles. There are six functions commonly used in trigonometry: sine (sin), cosine (cos), tangent (tan), cotangent (cot), secant (sec), and cosecant (csc).