1: sine theorem

a/sinA=b/sinB=c/sinC

2. Cosine theorem

Answer? =b？ +c？ -2bccosA

b？ =a？ +c？ -2accosA

c？ =a？ +b？ -2abcosA

3. Tangent interior theorem

Tan [(a-b)/2] = Tan (c/2) (a-b)/(a+b) or (a+b) tan[(A-B)/2]=(a-b)tan(C/2) or (a+b) tan.

The tangent theorem of other two diagonal relationships is the same.

Extended data

Triangle law, in short, is five mathematical laws. Sine theorem, cosine theorem, projection theorem in right triangle, large angle to large edge theorem, internal angle bisector theorem.

The function of this law is to judge the direction and potential of future trend through the angle and form of graphics in the early stage of the market. Use mathematical geometry to make a logical explanation of what people often say is "disk feeling"

This law is helpful to understand the structural relationship between large period and small period as a whole. There is an extremely accurate lock on the discovery of the critical point.

Triangle law is one of the most incisive theories to explain the trend structure.