Lesson 1

• What is formed when two rays meet at a common endpoint?

  An angle
• What are the rays forming an angle called?

  Sides
• What is the point at which the rays of an angle meet called?

  Vertex
• What is the initial side of an angle?

  It is the ray on the positive x-axis.
• What is the terminal side of an angle?


  It is the other ray.
• What is the standard position of an angle?

  When the vertex is at the origin and the initial side is on the positive x-axis.
• What are quadrantal angles?

  Angles whose terminal side coincides with one of the axes, such as 90°, 180°, 270°, or 360°.
• What does it mean if the terminal side of an angle rotates in a counterclockwise direction?

  The angle has a positive measurement.
• What does it mean if the terminal side of an angle rotates in a clockwise direction?

  The angle has a negative measurement.
• What angles should you illustrate using the coordinate plane system?

  • -90°
  • 250°
  • -320°
  • 400°
  • -720°
• What are coterminal angles?

  Different angles with the same initial side and terminal side.
• Are the following pairs of angles coterminal? 60° and 320°, 135° and 225°, 150° and 510°?

  • 60° and 320°: True
  • 135° and 225°: False
  • 150° and 510°: True
• What is the smallest positive angle coterminal with -45°?

  315°
• What is a reference angle?


  The angle that a given angle makes with the x-axis.
• How do you find the measure of the reference angle for given angles?

  • Measure the closest distance of the terminal side to the x-axis.
• What angles should you find the reference angle for?

  • 135°
  • 205°
  • 300°