How do you calculate the coordinates of centre of a rotation?
More information is needed to be able to answer this question. What shape are you rotating? The centre of rotation will be where the lines of symmetry intersect. If you can deduce the equations of two of the lines of symmetry & then solve them simultaneously, the result will be the coordinates of the centre of rotation. If you are talking about rotating a shape about a point outside the shape itself to another postion, you need to join corresponding points by straight lines. ie if you have a shape with vertices ABCD…. & rotate to a new position A’B’C’D’….., then you draw the lines AA’, BB’, CC’, DD’….. & construct the perpendicular bisectors of each line AA’, BB’, CC’, DD’….. These perpendicular bisectors will all meet at the centre of rotation. It is enough to draw two to find the centre of rotation , but you may want to draw more as a check. If you need to answer the question by calculation rather than construction, you will need to use the coordinates of your shape before &
