Students learn what it means for two figures to be similar in general, and then focus on triangles and what criteria predict that two triangles will be similar. Length relationships within and between figures are studied closely and foreshadows work in Module 2, Topic D. The topic closes with a look at how similarity has been used in real-world application.

Content Standard(s):

Mathematics MA2015 (2016) Grade: 9-12 Geometry

16 ) Use the properties of similarity transformations to establish the angle-angle (AA) criterion for two triangles to be similar. [G-SRT3]

Mathematics MA2015 (2016) Grade: 9-12 Geometry

17 ) Prove theorems about triangles. Theorems include a line parallel to one side of a triangle divides the other two proportionally, and conversely; and the Pythagorean Theorem proved using triangle similarity. [G-SRT4]

Mathematics MA2019 (2019) Grade: 9-12 Geometry with Data Analysis

27. Given two figures, determine whether they are similar by identifying a similarity transformation (sequence of rigid motions and dilations) that maps one figure to the other.

Alabama Alternate Achievement Standards

AAS Standard: M.G.AAS.10.24 When given two congruent triangles that have been transformed (limit to a translation), determine the congruent parts. (Ex: Determine which leg on Triangle A is congruent to which leg on Triangle B.)

Mathematics MA2019 (2019) Grade: 9-12 Geometry with Data Analysis

34. Use congruence and similarity criteria for triangles to solve problems in real-world contexts.

Alabama Alternate Achievement Standards

AAS Standard: M.G.AAS.10.36 Use geometric shapes to describe real-world objects.

Mathematics MA2019 (2019) Grade: 9-12 Geometry with Data Analysis

36. Use geometric shapes, their measures, and their properties to model objects and use those models to solve problems.

Alabama Alternate Achievement Standards

AAS Standard: M.G.AAS.10.36 Use geometric shapes to describe real-world objects.