Presentation on theme: "Lesson 4.2- Transformations on the Coordinate Plane, pg. 197"— Presentation transcript:
1Lesson 4.2- Transformations on the Coordinate Plane, pg. 197 Objectives:To transform figures by using reflections, translations, dilations, and rotations.To transform figures on a coordinate plane by using reflections, translations, dilations, and rotations.
2Vocabulary Transformations: movements of geometric figures. Pre-image: the position of the figure before the transformation.Image: the position of the figure after the transformation.
3Transformations on the Coordinate Plane Reflection- the figure is flipped over a line.Reflection over the x-axis:(x, y) (x, -y)Reflection over the y-axis:(x, y) (-x, y)
4Translation: a figure is slid in any direction. (x, y) (x + a, y + b)
5Dilation: a figure is enlarged or reduced. (x, y) (kx, ky)
6Rotation: a figure is turned around a point. (x, y) (-y, x)180° rotation:(x, y) (-x, -y)
7Ex. 1: Identify each transformation as a reflection, translation, dilation, or rotation. b)Translationc)Rotation
9Ex. 2: A trapezoid has vertices W(-1, 4) X(4, 4), Y(4, 1), and Z(-3, 1) A trapezoid is reflected over the y-axis. Find the coordinates of the image.Graph the trapezoid WXYZand its image W’X’Y’Z’
10Ex. 3: Triangle ABC has vertices A(-2,1), B(2, 4) and C(1,1) Find the coordinates of the vertices of the image if it is translated 3 units to the right and 5 units down.Graph the triangle ABCand its image.
11Ex. 4: A trapezoid has vertices E(-1, 2), F(2, 1), G(2, -1), and H(-1, -2) Find the coordinates of the dilated trapezoid E’F’G’H’ if the scale factor is 2.Graph the pre-imageand its image.
12SUMMARY Reflection- the figure is flipped over a line. Translation: a figure is slid in any direction.Dilation: a figure is enlarged or reducedRotation: a figure is turned around a point.Skills Practice Workbook, Lesson 4.2