Level 1
Level 2

Solving Non Right-angled Triangles Using the Sine


6 words 0 ignored

Ready to learn       Ready to review

Ignore words

Check the boxes below to ignore/unignore words, then click save at the bottom. Ignored words will never appear in any learning session.

All None

Ignore?
To use the Sine Rule
You need one complete ratio (Side to its opposite angle)
a/sinA = b/sinB = c/sinC OR sinA/a = sinB/b = sinC/c
This is used to find either a side or an angle in a non right-angled triangle. This is the Sine Rule. You do not need to use all three ratios, just one that you know and the one that you need to complete.
To use the Cosine Rule
You need to have two sides and the included angle
a²=b²+c²-2bc(cos)A
This is the equation for the Cosine Rule, it can be changed to have b or c as the subject (e.g. b²=a²+c²-2ac(cos)B).
You should use the Sine and/or Cosine Rule
When the triangle is non right-angled
You should use SOHCAHTOA
When the triangle is right-angled