12.4. Rotations http://www.ck12.org
It is very helpful to graph the triangle. IfAis( 7 , 4 ), that means it is 7 units to the right of the origin and 4 units up.
A′would then be 7 units to theleftof the origin and 4 unitsdown.The vertices are:
A( 7 , 4 )→A′(− 7 ,− 4 )
B( 6 , 1 )→B′(− 6 ,− 1 )
C( 3 , 1 )→C′(− 3 ,− 1 )
Example B
RotateST 90 ◦counter-clockwise about the origin.
Using the 90◦rotation rule,T′is (8, 2).