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Sides and opposite angles

Sides and opposite angles

Using the diagram below you can explore the relationship between the sine of an angle and the length of the opposite side in a triangle.

Question 1

Set the radius at 1. Divide the length of each of the sides, a, b and c by the value of the sine of the opposite angle A, B and C respectively. What do you notice?

Question 2

Set the radius at 2. Again, divide the length of each of the sides a, b and c by the value of the sine of the opposite angles A, B and C respectively. What do you notice this time?

Question 3

  • What conjecture can you make based on what you have seen so far.
  • Test out your conjecture...
  • What generalisation can you come to and how would you express it algebraically?