Google Classroom
GeoGebraGeoGebra Classroom

Dilating a Point (Intro)

The following applet illustrates what it means to dilate a point about another point.   You can move point O (the center of dilation) and point A anywhere in the plane.   You can also change the scale factor (k) of this dilation by either moving the slider or by typing it in the white box at the top of the applet. A' = the image of point A under dilation about point O with scale factor k.   Interact with the applet below for a few minutes BEFORE clicking the "Check This Out!" checkbox in the lower right corner.  After interacting with this applet for a bit, please answer the questions that follow the applet.  (You'll be prompted to click the "Check This Out!" checkbox in the directions below.)  
Questions:  (Please don't click the "Check This Out!" box yet!)   1) What vocab term would you use to describe the locations of point A and A' with     respect to O?  In essence, fill in the blank:  "The image of a point (A) under a dilation     about another point (O) is a point (A') that is _____________________ with O and A.   2) Click the "Check This Out!" box now.  Move point(s) O and A around.  Be sure to     adjust the scale factor (k) of this dilation as well.  Describe what you observe. 3) Answer the additional questions on the sheet provided to you in class.