Creating and Understanding Similar Figures using Geometer's Sketch Pad

Abstract

Goals: To review locating points in a coordinate system To predict how figures on a coordinate system are affected by a given rule To learn that corresponding angles of similar figures are equal and that corresponding sides grow by the same factor To compare lengths and angles in similar and non-similar figures informally To experiment with examples and counterexamples of similar shapes To understand that any two similar figures are related by a scale factor, which is the ratio of the corresponding sides To understand that the sides and perimeters of similar figures grow by a scale factor and that the areas grow by the square of the scale factor To recognize that triangles with equal corresponding angles are similar To use the definition of similarity to recognize when figures are similar To determine the scale factor between two similar figures