Tag Archives: sine rule

As I have done a cosine rule proof, I thought I should also do a sine rule proof.

From the above diagram, we can find in two ways.

(1)

(2)

Set equation 1 equal to equation 2

or

We could have put the altitude of the triangle from vertex A

Following the same process as above

(3)

(4)

Set equation 3 equal to equation 4.

Now therefore

or