Question

q1 - accelerated mathematics gr 8 | quiz 2

1. which of the following describes a 270 - degree counterclockwise rotation?

a. reflect the figure over the x - axis
b. swap the coordinates and negate the new y - coordinate
c. change both coordinates to their opposites
d. swap the coordinates and negate the new x - coordinate

Explanation:

A 270 - degree counter - clockwise rotation of a point (x, y) in the coordinate plane is equivalent to a 90 - degree clockwise rotation. The rule for a 90 - degree clockwise rotation is to swap the x and y coordinates and negate the new x - coordinate. Reflecting over the x - axis changes the sign of the y - coordinate only. Swapping coordinates and negating the new y - coordinate is for a 90 - degree counter - clockwise rotation. Changing both coordinates to their opposites is a 180 - degree rotation.

Answer:

d. Swap the coordinates and negate the new x - coordinate