Unit Circle with Labeled Key Angles (Unit Circle 3 Edited)

This example visualizes the unit circle by constructing multiple points and several labeled angles, illustrating how key angle measures correspond to specific locations on the circle. It reinforces core ideas of the unit circle, central angles (including angle/θ notation), and the geometric interpretation behind trigonometric relationships—especially how coordinate components on the unit circle connect to a Pythagorean-type relationship (the invariant sum of squares). Construction: GeoGebra commands Circle create the unit circle c; Point places points A, B, C, and D on the circle; Angle labels the angles α_2, α_3, α_4 and θ (Θ); Segment draws connecting helper lines; LaTeX and text objects (text1–text4) render mathematical labels and annotations. Key objects include c, A, B, C, Θ, D, α_2, α_3, α_4, a, and the accompanying text. Suitable for secondary school through early undergraduate instruction for learning trigonometry concepts, coordinate geometry intuition, and geometric graphing practice.