Question

The diagram shows r(90°, O)(ABCD). What are the coordinates of ABCD?

Answer 1

In order to determine the coordinates of ABCD, it is necessary to apply the following transformation to figure A'B'C'D':

r(-90°,0)(A'B'C'D')

or, which is equivalent, apply a clockwise rotation of 90°, which is represented as follow:

T(x,y) => (y,-x)

then, for the points A', B', C' and D', you obtain:

A'(2,1) => A(1,-2)

B'(-4,-2) => B(-2,4)

C'(-4,-6) => C(-6,4)

D'(-1,-3) => D(-3,1)