In Math 10C, trigonometry was used to find the measures of sides or angles in order to solve problems involving right triangles. In Math 20-1, the study of trigonometry will start by learning about angles found on the Cartesian plane. Later, you will apply the same trigonometric ratios learned in Math 10C to these angles.

In Lesson 4.1, you will

  • sketch an angle in standard position,
  • determine the quadrant in which an angle in standard position terminates,
  • determine the reference angle of an angle in standard position,
  • explain how to determine angles, from \(0^\circ\) to \(360^\circ\), that have the same reference angle, and
  • provide examples of points on the terminal arms of angles in standard position that have the same reference angle.