CK-12 Foundation
Ck 12: Interactive Geometry: 3.2 Asa and Aas Triangle Congruence
See how triangles are congruent where all corresponding angle pairs and sides are the same.
CK-12 Foundation
Ck 12: Interactive Geometry: 3.5 Applications of Congruent Triangles
Learn how two triangles are congruent if and only if their corresponding sides and corresponding angles are congruent.
CK-12 Foundation
Ck 12: Interactive Geometry: 13.3 Sas Triangle Congruence
See how two triangles are congruent it means that all corresponding angle pairs and all corresponding sides are congruent.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.5 Quadrilaterals
Explore and measure a variety of quadrilaterals.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.4 Triangles
Explore and measure a variety of triangles.
AAA Math
Aaa Math: Finding the Fourth Angle of a Quadrilateral
An interactive site that instructs and demonstrates how to find the fourth angle of a quadrilateral. This site also has many links to other interactive lessons.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Rhombus
This is a very brief look at the rhombus, which is a quadrilateral shape with four equal sides. Features include a JavaSketchpad that allows you to manipulate the shape.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Polyhedrons
This in-depth paper examines the idea of convexity. Euclid's Elements, the first geometry textbook, assumed convexity without mentioning the term.
Other
Ic Teachers: Shapes: Triangles
Are you looking for a very basic website that will explain the basic properties of a triangle? Use this site to learn about the properties of equilateral triangles, isosceles triangles, right triangles,and scalene triangles. There are...
Other
Ic Teachers: Shapes Quadrilaterals
Are you looking for a very basic website that will explain the basic properties of a quadrilateral? Use this site to learn about the properties of a square, rhombus, rectangle, parallelogram, trapezoid, and kite. There are also some...
ClassFlow
Class Flow: Quadrilaterals
[Free Registration/Login Required] This lesson goes deep into properties of parallelograms and special quadrilaterals. It has class interaction, student interaction, student practice, and whole class assessment.
Free Math Help
Free Math Help: Congruent Triangles
Students learn about congruent triangles. The tutorial consists of definitions and sample exercises with solutions.
Free Math Help
Free Math Help: Isosceles Triangles
Students learn about isosceles triangles. The tutorial consists of definitions and sample exercises with solutions.
Free Math Help
Free Math Help: Classification of Polygons and Triangles
The Geometry session explores the classification of polygons and triangles. Definitions and examples are included.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Congruent Angles
Find a quick, concise explanation of Congruent Angles. An example is given and clearly explained.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Congruent Triangles
Find a quick, concise explanation of Congruent Triangles. Several examples are given and clearly explained.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Parallelogram
Find a quick, concise explanation of a parallelogram. An example is given and clearly explained.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Trapezoid
Find a quick, concise explanation of what a trapezoid is. Examples are given and clearly explained.
ClassFlow
Class Flow: Congruency
[Free Registration/Login Required] Here are many variations of congruent triangles displayed for students to test their knowledge.
Free Math Help
Free Math Help: Angles
The lesson investigates different types of angles used in geometry. Definitions and examples are included.
Shmoop University
Shmoop: Basic Geometry: Basic Shapes & Angles
The geometry resource explores basic shapes, lines, and angles. Descriptions, examples, and practice problems are included.
Shmoop University
Shmoop: Basic Geometry: Triangles
The geometry resource explores triangles. Descriptions, examples, and practice exercises are included.
Shmoop University
Shmoop: Basic Geometry: Quadrilaterals
The geometry resource explores quadrilaterals. Descriptions, examples, and practice exercises are included.