Download Pre Calculus

Pre Calculus
4.1 Radian and Degree Measure
Name _________________________
Date ____________________
Trigonometry – “The measurement of triangles”
The study of angular, rotational and periodic behavior and its application to problem solving as functions.
Angles in the Coordinate Plane
An angle is formed from the intersection of two rays.
B
O
O ____________
OA _______________
A
OB ___________________
An angle with its vertex at the origin and its initial side on the x-axis is said to be in
________________ position.
Positive angles are formed by
________________ rotations.
Measuring Angles Degrees and Radians
Negative angles are formed by
_________________ rotations.
One degree is the angle formed by an arc equal to
1
th of a circle.
360
One radian is the angle formed by an arc equal to the radius of the circle.
Radian measures give the ratio of the arc and the radius of the full circle.
Conversions
Co-terminality
Angles with the same standard position, regardless of the direction or number of rotations of the terminal
side are called co-terminal angles.
Co-terminal angles are always of the form   n360 or   n2 where n is a positive or negative integer
representing the direction and number of rotations.
Exercises:
Convert the following to the opposite angle measure:
a.
80
b.
-144
d.
9
2
e.

5
12
c.
420
f.
7
9
Give two co-terminal angles for the following (one positive and one negative)
5

a.
250
b.
c.
2
3
4
90°
180°
360°
270°
90°
180°
360°
270°