What is the Projection Theorem?

Projection theorem

The so-called projection is the orthographic projection.

Among them, the vertical foot of a perpendicular line drawn from a point to a straight line is called the orthographic projection of this point on this straight line. A line segment between the orthographic projections of two endpoints of a line segment on a straight line is called the orthographic projection of the line segment on the straight line.

From the similar properties of triangles, we can get:

Theorem: In a right triangle, the height on the hypotenuse is the middle term of the ratio of the projections of the two right-angled sides on the hypotenuse. Each right-angled side is the median of the ratio between the projection of the right-angled side on the hypotenuse and the hypotenuse.

Formula: For the right angle ▲abc,

References: 1. Baidu knows