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

Trigonometry - Sine Rule.
Test Yourself 2.


 

Basic - find the length of a side
(answer to 2 dps).		    
     
     
  XYZ is a triangle in which ∠XYZ = 45°, ∠YXZ = 30° and the side YZ = 10 cm.

Find the length of side XZ to the nearest millimetre.

  
     
Side not opposite    
     
     
Basic - find the size of an angle. 17.  
     
     
     
Angle not opposite. 23.
What is the area of triangle ABC in the above diagram?		  
     
The ambiguous case. 25.

Find the value of the angle d° in the above triangle (to the nearest minute) - given that the angle is obtuse.

Answer.d° = 180° - 46° 4' = 133° 56'.		  
     
 

27. Let the angles in triangle ABC be x, y and z.

D is a point on BC such that AD bisects the angle at A.

Let BD = s and so DC = a - s

(i) In triangle ABD, show that .

(ii) Using triangle ADC, find the corresponding result.

(iii) Using both of the above results, prove that

.

(iv) State the result you have obtained in (iii) as a theorem (which is a very important theorem).