1. Finding a missing angle with inverse trigonometric functions
SOH-CAH-TOA
Finding a missing angle with inverse trigonometric functions

2. TO find an angle: Mark the angle that we are looking for with x or θ
Label the given sides in relation to x and decide which trigonometric function to use
Write an equation
Use your calculator (press the function key twice) to tell you the degree measure.

3. TO find an angle: Example 1
Hypotenuse
Opposite
𝑺𝒊𝒏 −𝟏 (𝒙)= 𝟓 𝟏𝟒
Mark the angle that we are looking for with x or θ
Label the given sides in relation to x and decide which trigonometric function to use
Write an equation
Use your calculator (press key twice) to tell you the degree measure
Type this
in your calculator
𝑺𝒊𝒏 −𝟏 ( 𝟓 𝟏𝟒 )
𝒙= 20.92˚

4. TO find an angle: Example 2
Hypotenuse
Adjacent
𝑪𝒐𝒔 −𝟏 (𝒙)= 𝟓 𝟏𝟐
Mark the angle that we are looking for with x or θ
Label the given sides in relation to x and decide which trigonometric function to use
Write an equation
Use your calculator (press key twice) to tell you the degree measure
Type this
in your calculator
𝑪𝒐𝒔 −𝟏 ( 𝟓 𝟏𝟐 )
𝒙= 65.38˚