This lesson unit is intended to help teachers assess how well students are able to: work with concepts of congruency and similarity, including identifying corresponding sides and corresponding angles within and between triangles; Identify and understand the significance of a counter-example; Prove, and evaluate proofs in a geometric context.

CK-12 Foundation's Geometry FlexBook is a clear presentation of the essentials of geometry for the high school student. Topics include: Proof, Congruent Triangles, Quadrilaterals, Similarity, Perimeter & Area, Volume, and Transformations.

Students understand that similarity is reflexive, symmetric, and transitive.
Students recognize that if two triangles are similar, there is a correspondence such that corresponding pairs of angles have the same measure and corresponding sides are proportional. Conversely, they know that if there is a correspondence satisfying these conditions, then there is a similarity transformation taking one triangle to the other respecting the correspondence.

Interactive tool that allows students to use skills about center and scale factor.

This is a PBL project that asked students to select a select a major period/style of architecture in history, research it to see how this genre influenced the major architectural design elements, and then synthesize the information as part of a redesigned college campus. The final designs are presented to working architects and used as a basis to prove key geometry standards in the Math 2 curriculum.

Reference sheet for students and/or teachers that describes everything necessary to understand transformations and congruence and simalirity

Students sketch triangles in a coordinte plane and make a series of conjectures for what occurs mathematically when you multiply coordinates by various numbers.

One purpose of this task is to continue to solidify the definition of dilation: A dilation is a transformation of the plane, such that if O is the center of the dilation and a non-zero number k is the scale factor, then P’ is the image of point P if O, P and P’ are collinear. A second purpose of this task is to examine proportionality relationships between sides of similar figures by identifying and writing proportionality statements based on corresponding sides of the similar figures. A third purpose is to examine a similarity theorem that can be proved using dilation: a line parallel to one side of a triangle divides the other two proportionally.

One purpose of this task is to continue to solidify the definition of dilation: A dilation is a transformation of the plane, such that if O is the center of the dilation and a non-zero number k is the scale factor, then P’ is the image of point P if O, P and P’ are collinear.