Grade 6 • 1yr.
How to rotate a 2d shape 90 degrees around the center of rotation?
How to rotate a 2d shape 90 degrees around the center of rotation?
Explanation from Alloprof
This Explanation was submitted by a member of the Alloprof team.
Hi!
Rotating a 2D shape 90 degrees around its center means turning the shape so that every point moves 90 degrees around that center, kind of like turning a wheel!
First, make sure you know where the center of rotation is (it’s the point the shape spins around). If the shape rotates 90 degrees clockwise, each point moves a quarter turn to the right. If it’s 90 degrees counterclockwise, the points move a quarter turn to the left.
In terms of coordinates, if a point (x, y) rotates 90 degrees counterclockwise, its new position will be (−y, x). If it rotates 90 degrees clockwise, the new position will be (y,−x).
I hope it's clearer for you! :)
PS: If you have a particular exercise that is giving you trouble, you can send us a photo of it, we'll be happy to help you!