To calculate a missing length in a triangle, you can use one of the three trigonometric ratios. The length of another side and an angle other than the right angle has to be provided.
Calculating a length in a triangle
PROCEDURE
1.
Label the sides and angle of the triangle.
2.
Work out what trigonometric ratio you have to use (SOH, CAH or TOA).
3.
Write down and rearrange the formula to make your missing side the subject.
4.
Substitute in your values for the other side and the angle to get the length.
Example 1
Find the value of the side labelled x in the diagram given to 1 decimal place.