• The area of a triangle using Area = ½ ab sin C and use of this formula
Alison.com Finding areas with trigonometry
• The connection between this formula and the geometric approach to the area of a triangle
Khan
video Area of inscribed equilateral triangle (some basic trig used)
• How to derive the sine rule
Alison.com Proving the Sine Rule
Khan
video Proof: Law of sines
• Uses of the sine rule to solve real life problems
Khan
• How to derive the cosine rule
Alison.com Proving the Cosine Rule
Khan
video Proof of the law of cosines
• The uses of the cosine rule to solve real life problems
Khan
Law of sines and law of cosines word problems
• Use of the clinometer