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

2 The Sine Rule – Finding a Side (1/3) a Sin A A a B b C c = b Sin B = c Sin C To use the Sine Rule to find a side … we need two angles and … the sides opposite them.

3 The Sine Rule – Finding a Side (2/3) a Sin A a 46 o 12cm = b Sin B To use the Sine Rule to find a side we need two angles and the sides opposite them. 85 o a Sin 85 o = 12 Sin 46 o x Sin 85 o Sin 85 o x a = 12 Sin 46 o x Sin 85 o = … ≈ 16.6 cm WebGame

4 The Sine Rule – Finding a Side (3/3) b Sin B b 57 o 8 m = a Sin A To use the Sine Rule to find a side we need two angles and the sides opposite them. 83 o b Sin 40 o = 8 Sin 83 o x Sin 40 o Sin 40 o x b = 8 Sin 83 o x Sin 40 o = … ≈ 5.2 m B First find angle B. B + 83 o + 57 o = 180 o B o = 180 o B = 40 o 40 o