![]() So from 0 degrees you take (x, y) and make them negative (-x, -y) and then you've made a 180 degree rotation. When you rotate by 180 degrees, you take your original x and y, and make them negative. If you have a point on (2, 1) and rotate it by 180 degrees, it will end up at (-2, -1) Rotations may be clockwise or counterclockwise. An object and its rotation are the same shape and size, but the figures may be turned in different directions. We do the same thing, except X becomes a negative instead of Y. A rotation is a transformation that turns a figure about a fixed point called the center of rotation. If you understand everything so far, then rotating by -90 degrees should be no issue for you. Our point is as (-2, -1) so when we rotate it 90 degrees, it will be at (1, -2)Īnother 90 degrees will bring us back where we started. What about 90 degrees again? Same thing! But remember that a negative and a negative gives a positive so when we swap X and Y, and make Y negative, Y actually becomes positive. Our point is at (-1, 2) so when we rotate it 90 degrees, it will be at (-2, -1) Use a protractor to measure the specified angle counterclockwise. Now, with the interactive below, practice. The amount of rotation is called the angle of rotation and it is measured in degrees. The opposite of 5 is -5 and, switching the coordinates, you obtain your answer: (8, -5). The rule for rotating an object 270 clockwise about the origin is to take the opposite value of the x-coordinate and then switch it with the y-coordinate. The rotations around X, Y and Z axes are known as the principal rotations. See interactive diagrams and try different angles and shapes with Mathopolis. What if we rotate another 90 degrees? Same thing. Rotate the point (5, 8) about the origin 270 clockwise. Learn what rotation means in geometry and how to rotate shapes around a center. So from 0 degrees you take (x, y), swap them, and make y negative (-y, x) and then you have made a 90 degree rotation. ![]() When you rotate by 90 degrees, you take your original X and Y, swap them, and make Y negative. If you have a point on (2, 1) and rotate it by 90 degrees, it will end up at (-1, 2) In case the algebraic method can help you:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |