Angles and Their Measures

1
Angles and Their Measures

• 4.1

2
Be able to state what a radian is

• A central angle of a circle has measure 1 radian
  if it intercepts an arc with the same length as
  the radius.

3
Be able to convert from radians to degrees.

• 180 degrees is equivalent to p radians.
• Set up a proportion and solve.

4
Be able to find an arc length, a radius, or an
angle measure using either formula

• 1. s r ?
• S length of intercepted arc
• R length of radius
• T measure of angle in radians
• 2. s (? p /180) r
• ? in degrees
• OR
• Convert Degrees to radians, then s r ?.

5
Be Able to Solve Angular and Linear Motion Story
Problems

• 1 Revolution 1 circumference
• Unit Analysis
• Circumference formula
• C 2pr

6
Be Able to Solve Angular and Linear Motion Story
Problems

• Theresa drives a car with the diameter of the
  wheels being 28.04 inches. When she travels at a
  speed of 65 miles per hour, how many revolutions
  are her tires making per minute?

7
Trigonometric Functions of Acute Angles

• 4.2

8
Trigonometric Functions

• Sine (?) opp/hyp cosecant ? hyp/opp
• Cosine (?) adj/hyp secant ? hyp/adj
• Tangent (?) opp/adj cotangent ? adj/opp

9
Be Able to find the Six Trigonometric Functions
given sin(?)2/3 or similar.

• Sin (?) opp/hyp csc ? hyp/opp
• Cos (?) adj/hyp sec ? hyp/adj
• Tan (?) opp/adj cot ? adj/opp

?
10
Be able to Find the Trig Functions on the
Calculator

• Make sure the mode is radian/degree depending on
  your need.
• There are no buttons on the calculator for sec,
  csc, or cot.
• Use 1/(the appropriate trig) to get these.
• Watch Parenthesis

11
Be able to Solve Word Problems Involving the Trig
Functions

• To calculate the height of a tree, a surveyor
  measures the angle of elevation to be 34 degrees.
  She measures a distance of 8 m from her to the
  base of the tree. How tall is the tree?