Traditional Culture Encyclopedia - Photography and portraiture - The explanation and application of projective theorem should be detailed as follows.

The explanation and application of projective theorem should be detailed as follows.

Similar to a right triangle:

BD？ =AD*CD，

AB？ =AD*AC，

BC? =CD*AC，

These three are called projective theorems.

Main uses:

Of the six line segments, knowing two is four.

Pythagorean theorem can be proved by projective theorem and pure geometric method.