Dr. J's Maths.com
Where the techniques of Maths
are explained in simple terms.

Trigonometry - Cosine rule.
Test Youself 1 - Solutions.


 

Find a side 1.
  2.
     
     
     
  6.  
Find an angle.

7. We are dealing with 3 sides and one angle and need to find the angle:
 

8. We are dealing with 3 sides and one angle and need to find the angle:
  9.

The smallest angle is always opposite the smallest side.
     
     
  11.  
Practical problems.

13. David is playing golf on a hole which is 330 m long. He hits a good drive of 220 m but pulls it a little and the ball goes straight but to the left at an angle of 8°.

How far is David's second shot to the hole?