Point A is the original point before rotating. Which point represents A′ after A(4, 1) is rotated 90° counterclockwise: B, C, D, E, F, G, or H?

2 answers

To rotate a point counterclockwise by 90°, we need to swap the x- and y-coordinates and negate the new x-coordinate.

For point A(4, 1), swapping the x- and y-coordinates gives us A′(1, 4). Negating the new x-coordinate gives us A′(-1, 4).

Out of the given points B, C, D, E, F, G, and H, the only point that represents A′(-1, 4) after rotating A(4, 1) counterclockwise by 90° is D.
G