finding an angle
LEARNING INTENTION: To determine the unknown angle of a right angled triangle when given two side lengths using trigonometric functions.
SUCCESS CRITERIA: - I know what SOH CAH TOA stands for and how to use it - I can use the appropriate inverse function for (sin, cos or tan) - I can transpose the equation to make theta the subject. |
EXERCISES FROM TEXT
Ex 3H 2, 3adg, 5-8 Extension: 10, 13 |
![Picture](/uploads/3/0/5/6/30566275/finding-angle_orig.png)
When we know the length of two sides in a Right Angle triangle but not the included angle then use the inverse of the trigonometry rules.
STEPS
- Label the sides
- Look to see which sides form the angle and/or have measurements on them
- Choose the appropriate function to use (SOH CAH TOA)
- Substitute your known values in
- Solve to find the value of θ
Hint: To do this on your calculator;
press SHIFT then Cos
then type (ratio) &
press enter