9.4 Perform Rotations Translations http://www.mathsisfun.com/flash.php?path=%2Fgeometry/images/translation.swf&w=894&h=762&col=%23FFFFFF&title=Geometry+Translation Vector/Translations http://illuminations.nctm.org/LessonDetail.aspx?id=L474 Rotations http://illuminations.nctm.org/LessonDetail.aspx?ID=L466# rotational symmetry http://illuminations.nctm.org/LessonDetail.aspx?ID=L468

Rotation A rotation is a transformation in which a figure is turned about a fixed point called the _____________________ *** A counterclockwise rotation is a _______ rotation *** A clockwise rotation is a _______ rotation. Rays drawn from the center of rotation to a point and its image form the __________________________. CENTER OF ROTATION positive negative A transformation that turns a figure about a fixed point called the center of rotation.  An object and its rotation are the same shape and size, but the figures may be turned in different directions.   Amusement rides, such as the ferris wheel and the swing, allow you to experience the concept of rotation. Rotations can be seen in planetary movement. ANGLE OF ROTATION

EXAMPLE 1 Draw a 150° rotation of ∆ABC about the origin. A B C C’ B’

Example 2: Draw a 60° rotation of ∆GHJ about the given point.

Rotations - b a hyperlink - a - b b - a ( b, -a)

Example 3: Graph quadrilateral KLMN with vertices K(3, 2), L(4, 2), M(4, -3), and N(2, -1). Then rotate the quadrilateral 270° about the origin. Since you have a 270° rotation, the rule you’ll use is: (a, b) → ________________

Example 4: Graph quadrilateral KLMN with vertices K(3, 2), L(4, 2), M(4, -3), and N(2, -1). Then rotate the quadrilateral 90° about the origin. (a, b) → ______________

Is a rotation an Isometry? Yes!!

EXAMPLE 5 The quadrilateral is rotated about P. Find the value of y.

Example 6: The triangle is rotated about P. Find the value of b.

Let’s Check! http://regentsprep.org/regents/math/geometry/GT4/PracRot.htm