1. ©G Dear2008 – Not to be sold/Free to use
General Mathematic
(HSC)
Further
Trigonometry
Sine Rule - Angle
Stage 6 - Year 12
Press Ctrl-A
©G Dear2008 – Not to be sold/Free to use

2. The Sine Rule – Finding an Angle (1/2)c b B a C
Sin A a
Sin B b
Sin C c = =
To use the Sine Rule to find an angle …
we need two angles and …
the sides opposite them.

3. The Sine Rule – Finding an Angle (2/2)
Sin A a
Sin B b A =
4 cm
Sin A 5
X 5
Sin 40 4
X 5 =
5 x Sin 40 4
Sin A =
40o
5 cm
Sin-1 ( )
5 x Sin 40 4 A =
≈ 54o