When reflection is done around the x axis, he x axis remains the same but the y coordinate is transformed (the sign changes)
When reflection is done around the y axis, he y axis remains the same but the x coordinate is transformed (the sign changes)
Thus, reflection across the x axis would not result in a graph with 2 perpendicular lines.
A rotation turns the pre- image about a fixed point which is also called the center of rotation. Given that y = 0, a counterclockwise rotation of 270 degrees would result in a graph with 2 perpendicular lines.