1. Material Taken From: Mathematics for the international student Mathematical Studies SL Mal Coad, Glen Whiffen, John Owen, Robert Haese, Sandra Haese and Mark Bruce Haese and Haese Publications, 2004

2. Solving Triangles Chapter 10 – Section H: The Sine Rule
To solve a non-right triangle you need at least 3 pieces of information:
3 sides
2 sides & the angle between
2 sides & an angle opposite
2 angles & 1 side
SSS
SAS
SSA
ASA, AAS

4. Sine Rule
SSA A C B a b c
ASA, AAS

5. 1) Find the length of AC.

6. 2) Find the length of AB.
Math 3 textbook example 14, pg255

7. 3) In the diagram, triangle ABC is isosceles
3) In the diagram, triangle ABC is isosceles. AB = AC, CB = 15 cm and angle ACB is 23°.
Find:
(a) the size of angle CAB;
(b) the length of AB. A C B
23º
15 cm
Studies, May 1999, paper 1, question 19
Diagram not to scale

8. 4) A farmer wants to construct a new fence across a field
4) A farmer wants to construct a new fence across a field. The plan is shown below.
The new fence is indicated by a dotted line. Calculate the length of the fence.
75°
40°
410 m
Studies, May 2005, paper 2, question 2
Diagram not to scale

9. 5) The figure shows a triangular area in a park surrounded by the paths AB, BC and CA, where AB = 400 m.
(a) Find the length of AC using the above information.
Diana goes along these three paths in the park at an average speed of 1.8 m/s.
(b) Given that BC = 788m, calculate how many minutes she takes to walk once around the park.

10. 6) In triangle ABC, AC = 5, BC = 7, A = 48°, as shown in the diagram
Find the measure of angle ABC giving your answer correct to the nearest degree. A B C 5 7
48°
SL, Nov 2002, paper 1, question 2
diagram not to scale

11. (b) Find the area of triangle PQR
7) The diagram below shows triangle PQR. The length of [PQ] is 7 cm, the length of [PR] is 10 cm, and PQR is 75°.
(a) Find PRQ
(b) Find the area of triangle PQR
SL, May 2008, paper 2, timezone 1, question 2
diagram not to scale

12. Homework
Worksheet
#1abef
#2a
#3ace
Pg 341 – H.1 2abc