What Are Scaled Copies?

Warmup


Activity #1

Observe the Effect of Scaling on an Image.

Here is a portrait of a student. Move the slider under each image, A–E, and observe the change.


Activity #2

To Match Scaled Copies of Polygons.

In the applet below is a set of cards that have polygons drawn on a grid. Display the cards face up by clicking on them, then match a pair of polygons that are scaled copies of one another.

(1). Select one pair of polygons and use the segment tool on the grid below to produce both polygons. Explain or show how you know that one polygon is a scaled copy of the other.

(2). Is it possible to draw a polygon that is a scaled copy of both Polygon A and Polygon B? Either draw such a polygon, or explain how you know this is impossible.


Activity #3

To Create Scaled Copies.

1. Draw two scaled copies of the figure on the grid below using a scale factor of 2 and 1/2.

2. Draw two scaled copies for Figure B on the grid below using a scale factor of 3 and 1.5

Look at the triangles in the graph below and answer the question that follows.


Summary


Challenge #1

Tyler says that Figure B is a scaled copy of Figure A because all of the peaks are half as tall.

Do you agree with Tyler? Explain your reasoning.


Challenge #2

Here below is a figure that looks like the letter A, along with several other figures. Which figures are scaled copies of the original A?

(2). Explain how you know.


Challenge #3

Here is a picture of the Rose Bowl Stadium in Pasadena, CA.