The square root of 72 is rational because the answer can be a real number.
Find their gradients using the change in y coords divided by the change in x coords. once you have the gradients (or slopes), multiply them by eachother - if the product is (-1) then theyre perpdendicular, if not, they are either parallel or intersect at a point
<em>Look</em><em> </em><em>at</em><em> </em><em>the</em><em> </em><em>att</em><em>ached</em><em> </em><em>picture</em>
<em>hope</em><em> </em><em>it</em><em> </em><em>will</em><em> </em><em>help</em><em> </em><em>u</em><em> </em><em>.</em><em>.</em><em>.</em><em>.</em>
The triangle will be rotated with the rule of (x,y) → (-y,x). The image will be congruent to the pre-image, the side lengths will be the same and the angles too.