What is the projective theorem? What is it like?

Projection theorem of right triangle (also called Euclid theorem): In a right triangle, the height on the hypotenuse is the proportional average of the projections of two right angles on the hypotenuse. Each right-angled edge is the median of the projection of this right-angled edge on the hypotenuse and the proportion of the hypotenuse.

formula

For rt△abc, ∠bac=90 degrees, and ad is the height on the hypotenuse bc, the projective theorem is as follows:

(ad) 2 = BD Special Zone, (1)

(AB BC) 2 = BD ②

(BC AC) 2 = CD

. (3)

This is mainly introduced like a triangle, for example, (AD) 2 = BD DC: