How to get a rotated line?

Question

Geometry

How can I get the coordinates of a rotated (for example, 47%) line (x1, y1, x2, y2)?
Maybe there is some kind of algorithm?
I don’t know what else to write, but if you need something, write in the comments.
Thank you.

Answer 1

What does it mean to rotate by 47%? Percentage of what? From 180 degrees, from 360?
Around which point to turn?
Put a pencil on the table. Relative to the left near corner of the table, it has the coordinates of the ends. You can measure x1, y1, x2, y2 with a ruler.
Now rotate the pencil by 47%. I would even watch a vid.

Answer 2

I started doing this back in class 8, and there is no analytical geometry there, but I started because I was learning to program 3d graphics, so references to the university are not very appropriate sometimes
you need to multiply the vectors drawn from the origin to the start / end point of the line by the rotation matrix
each of these vectors
, the resulting vectors will point to the beginning and end of the segment rotated around the origin of the coordinate system (points 0,0
) are transferred back. all this can be done using matrices, and you can calculate one matrix at once for 3 transformations
google about transformation matrices / graphics programming and read the basics