Find the equation for the line of reflection that places point C' at (0,1), B' at (-1,0), and A' at (-3,3).
You should have found the equation[math]y=-x+4[/math]. Playing with the sliders with a little detective work should get you there.
After you are sure you have Question 2 correct, draw a line [icon]/images/ggb/toolbar/mode_join.png[/icon] connecting each of the points on the preimage to their corresponding points on the image (ie, connect A to A', B to B', and C to C'). What is the slope of the lines you have drawn? What is the relationship of these lines to the line of reflection? Hint, look at the angle between the line of reflection and any line that you drew. You can do this by selecting the angle [icon]/images/ggb/toolbar/mode_angle.png[/icon] tool and then clicking the two lines you'd like the angle between.
The slope should be -1, and this means the lines are perpendicular. That means the angle between the lines is 90 degrees.
Move on the Exploring Reflections 3.