Trigonometric ratios of an acute angle in a right-angled triangle, illustrating definitions and formulas for sine, cosine, tangent, cosecant, secant, and cotangent.
Diagram showing trigonometric ratios (T-ratios) of an acute angle in a right-angled triangle, with labels for sides (base, perpendicular, hypotenuse) and definitions of sine, cosine, tangent, cosecant, secant, and cotangent.