Mathematics is a subject full of mystery and charm. In this field, there are many seemingly unrelated numbers and relationships, but after our reasoning and exploration, you will find a mysterious connection between them. This paper will take you into this fascinating mathematical world and explore its mystery and relationship.

Equality?

There are equal possibilities between these three numbers! This seems unexpected, but if you reason carefully, you will find it is true.

Want to add it to 180?

If you add up these three numbers, the result is 180! Is this a magical coincidence, or is there a deeper mathematical mystery hidden in it?

EF=BE+AF

This is a geometric problem. Add BE and AF to get EF. This seems simple, but there is a fascinating geometric principle behind it.

CBE=ACD

This is a key proof step. Through a series of rigorous reasoning and calculation, we finally proved that CBE and ACD are equivalent. This proof process shows the rigor and accuracy of mathematics.