Question 851323
<pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
Rotation 90 degrees counterclockwise about the origin 
In ALL cases <u>Sketch it</u>, as long as You get the right angle, all is well
(2,5)&(5,-2)   (0,4) & (4,0)
{{{drawing(300,300,   -6, 6, -6, 6, grid(1), 
red(circle(2, 5,0.3)),
red(circle(5, -2,0.3)),
red(line(2,5,0,0)),
red(line(5,-2,0,0)),
green(circle(0, 4,0.3)),
green(circle(4, 0,0.3)),
graph( 300, 300, -6, 6, -6, 6) )}}}
(2,-1)&(-1,-2)   (3,0) & (0,3)
{{{drawing(300,300,   -6, 6, -6, 6, grid(1), 
red(circle(2, -1,0.3)),
red(circle(-1, -2,0.3)),
red(line(2,-1,0,0)),
red(line(0,0,-1,-2)),
green(circle(0, 3,0.3)),
green(circle(3, 0,0.3)),
graph( 300, 300, -6, 6, -6, 6) )}}}