13.2 – Coterminal Angles
Objective: TSW draw angles is
standard position and calculate
coterminal angles.
Angle in Standard Position
The Unit Circle – Introduction
1. Circle with radius of 1
1 Revolution = 360°
2 Revolutions = 720°
2. Positive angles move
counterclockwise around
the circle
3. Negative angles move
clockwise around the circle
Quadrantal Angles (positive)
Angles in standard position whose terminal side
is on the x or y axis.
Quadrantal Angles (negative)
Angles in standard position whose terminal side
is on the x or y axis.
Draw an angle with the given measure
in standard position:
1. 45°
2. -130°
3. 230°
Coterminal Angles
co – terminal
with, joint,
or together
ending
Coterminal Angles – angles that end at the
same spot
What do coterminal angles look like?
http://www.mathopenref.com/coterminal.html
Find a coterminal angle for each of the
following angles.
4. 70°
6. –20°
5. 250°
7. –220°
Your Turn, find two positive and two negative
coterminal angles.
8. 45°
9. 250°
10. –20°
Solving for coterminal angles of least
measure
If the angle is
If the angle is
positive, subtract negative, add 360°
360° from the given to the given angle.
angle.
You know you are done when your angle
measure is positive, and less than 360°
Find the angles of least positive
measure coterminal with each angle.
11. 1106°
12. -150°
Your Turn…
13. –603°
14. 1500°
Application…Your Try
15. A wheel makes 270 revolutions per minute.
Through how many degrees will a point on the
edge of the wheel move in 5 sec?
Homework
Pg. 820: 1-6; Pg. 821: 12-24(even)