Traditional Culture Encyclopedia - Photography and portraiture - What is the projective law and how to prove it; what should I do if I don’t understand the question about the equal product formula?
What is the projective law and how to prove it; what should I do if I don’t understand the question about the equal product formula?
Expand
Projection Theorem
Theorem: In a right triangle, the height on the hypotenuse is the median of the ratio of the two right-angled sides projecting onto the hypotenuse, A right-angled side is the median of the ratio between the projection of this right-angled side on the hypotenuse and the hypotenuse.
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. Projection theorem;
Suppose right triangle ABC, AB is the hypotenuse and CD is the height, then
The square of AC = AD×AB
The square of CB = BD×BA
The square of CD = AD×DB
Equal product formula;
AD×AC=AB×AC
Explanation ;AC/AB=AC/AD (proportional formula)
∠ACB=90°, CD⊥AB, then AC^2=AD×AB, BC^2=BD×AB,CD^2= AD×BD. The above proportional formulas are collectively called the projection theorem. It is mainly used to solve the problem of the hypotenuse of a right triangle and the connection between the fixed point and the hypotenuse. For example, given the lengths of AD and BD, find AC:BC.
I hope it can help you, please give a "good review"
- Previous article:What should I pay attention to when taking Japanese wedding photos?
- Next article:Is Nantong stunning photography effective?
- Related articles
- Is it easy to find a job after learning photography?
- Copy of graduation from dormitory
- How to write the work plan of a community minister?
- What happened to the love nest? How to do the task?
- What does ACG· Cuso mean?
- Who has Jason's Untimed Time TXT and Nana's Na writes time and Na is a gust of wind? Can you send them to me? wangyueying98@ 126.com
- What is the nature of the access card for the underground garage in Tsinghua Campus? Ic card or ID card?
- Can the brightness of Fuji xt4 viewfinder be adjusted?
- What powerful PS plug-ins are there?
- Ancient words describing women