Assume P(xp,yp), A(xa,ya), etc. We know that rotation rule of 90<span>° clockwise about the origin is R_-90(x,y) -> (y,-x) For example, rotating A about the origin 90</span><span>° clockwise is (xa,ya) -> (ya, -xa) or for a point at H(5,2), after rotation, H'(2,-5), etc.
To rotate about P, we need to translate the point to the origin, rotate, then translate back. The rule for translation is T_(dx,dy) (x,y) -> (x+dx, y+dy)
So with the translation set at the coordinates of P, and combining the rotation with the translations, the complete rule is: T_(xp,yp) R_(-90) T_(-xp,-yp) (x,y) -> </span>T_(xp,yp) R_(-90) (x-xp, y-yp) -> T_(xp,yp) (y-yp, -(x-xp)) -> (y-yp+xp, -x+xp+yp)
Example: rotate point A(7,3) about point P(4,2) => x=7, y=3, xp=4, yp=2 => A'(3-2+4, -7+4+2) => A'(5,-1)
I'm assuming you're looking for the dimensions of the plot. I'm going with that. ;) If the length of the plot is 5 meters longer than the width, then L = w + 5. The area for a rectangle is L*w, and we have an area value of 20,000 so our formula is 20000=(w+5)(w) and . We will bring the 20,000 over by subtraction and set the polynomial equal to 0 to factor and solve for w. Solving for w we get values of w=138.9 and -143.9. Of course the 2 things in math that will never EVER be negative are time and distance/length, so -143.9 is out. Our width is 138.9 and the length is 138.9 + 5 so the length is 143.9. And there you go! Hope that's what you needed!