Question

Quadrilateral ABCD has vertices A = (2, 5), B = (2, 2), C = (4, 3), and D = (4, 6). Quadrilateral A'B'C'D' is formed when Quadrilateral ABCD is rotated 90° counterclockwise about point origin. What are the coordinates of quadrilateral A'B'C'D'?

Answer 1

Rotation through 90° counterclockwise has the mapping.

$(x \: ,\: y) \: \rightarrow( - y \: ,\: \: x)$
$A(2 \: \:,5) \: \rightarrow \: A' ( - 5 \: \:,2)$

$B(2 \: , 2) \: \rightarrow B'( - 2 \: , \: 2)$

$C(4 ,\: \: 3) \: \rightarrow C'( - 3, \: \: 4)$

$D(4 ,\: \: 6) \: \rightarrow D' ( - 6, \: \: 4)$