After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of...

Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...

Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet. 

Scholars can use area formulas, but can they apply what they know about area? The lesson challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...

Explains the basic concept of similar triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

[Free Registration/Login may be required to access all resource tools.] An overview of altitudes and geometric mean is provided in this study guide.

Models how to write a similarity statement about different types of triangles and quadrilaterals.

[Free Registration/Login may be required to access all resource tools.] This study guide looks at similar polygons, scale factor (ratio), and triangle similarity.

[Free Registration/Login may be required to access all resource tools.] This study guide looks at several examples of self-similarity.

This site defines parallel lines, parallel lines cut by a transverse, and congruent triangles. It also contains links for related terms.

[Free Registration/Login may be required to access all resource tools.] This study guide looks at the definitions and units for perimeter, area, and circumference, and at the perimeter and area of different shapes, including regular...

This site defines eleven theorems relating to parallel lines and similar and congruent triangles. Links to the theorems and relevant term descriptions are provided.