A triangle has three angles.

(1) square relation

Three shadow triangles, the sum of the squares of the upper two angles is equal to the square of the lower one.

Namely. Sin? A+cos？ A= 1，？ Tan? A+ 1 = seconds? First, Kurt? A+ 1=csc？ A

(2) Reciprocal relationship,

The two endpoints on the diagonal are reciprocal.

Namely. Sina *cscA= 1,? cosA*secA= 1，？ tanA*cotA= 1

(3) business relations,

Three adjacent vertices of a hexagon satisfy the middle number = the product of both sides (which can be changed to the ratio form).

Namely. Sina =cosA*tanA?

tanA=sina*cscA

secA=tanA*cscA

cscA=secA*cotA

cotA=cscA*cosA

cosA=cotA*sinA