# Dilating a Point (Intro)

- Author:
- Tim Brzezinski

The following applet illustrates what it means to dilate a point about another point.
You can move

**point**and*O*(the center of dilation)**point**anywhere in the plane. You can also change the*A***scale factor (**of this dilation by either moving the slider or by typing it in the white box at the top of the applet.*k*)*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 (**that is _____________________ with

*A'*)*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.