This trigonometry learning tool is engineered for high-school Math I / Math II students, university calculus and engineering-math students, SAT / AP Precalculus / IB Math candidates, and professionals in physics, electrical engineering, architecture, land surveying, and computer graphics who apply trigonometric concepts daily. An interactive unit circle (radius = 1) lets you drag the angle θ to visually observe the geometric definitions of sin (y-coordinate), cos (x-coordinate), and tan (slope) in real time—finally making it intuitive why sin corresponds to the y-axis. A parametric wave-graph simulator for y = A·sin(Bx − C) + D reveals how amplitude (A), period (B), phase shift (C), and vertical offset (D) transform sinusoidal curves. Supply two sides and the included angle and the built-in triangle solver instantly returns the remaining sides, all interior angles, area, and perimeter using the Law of Cosines, Law of Sines, and Heron's formula. Reference identities—Pythagorean (sin²θ + cos²θ = 1), quadrant sign rules (ASTC: All-Students-Take-Calculus), and radian/degree conversion (180° = π rad)—complete a concept-visualization-computation-verification learning loop.

• Pythagorean Identity: sin²θ + cos²θ = 1, 1 + tan²θ = sec²θ
• Tangent Definition: tan θ = sin θ / cos θ
• Law of Cosines: c² = a² + b² - 2ab·cos(C)
• Triangle Area: S = ½·a·b·sin(C)
• Radian Conversion: rad = deg × (π / 180)