Virginia Department of Education
Classifying Angles
Don't be obtuse, this geometry unit is the just the right resource for educating the acute young minds in your class. From classifying and measuring angles, to determining the congruence of shapes, this...
Mathematics Vision Project
Module 5: Modeling with Geometry
Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts...
PBS
Accessible Shapes
All the 2-D and 3-D measurement work you need is in one location. Divided into three sections, the geometry lesson plans consist of visualization of three dimensions, classifying geometric figures, and finding surface area and volume....
Cuemath
Cuemath: Right Angled Triangle
Explore and learn about the features and properties of a right triangle in this lesson. Includes examples and practice questions.
National Council of Teachers of Mathematics
The Math Forum: Triangle Formulas
Investigate the geometric definitions of triangles, focusing upon equilateral, isosceles, right, and scalene with detailed drawings and appropriate formulas for each. This site has links to more information on triangles.
Cuemath
Cuemath: Altitude of a Triangle
Explore the world of the altitude of a triangle in this mini-lesson including its definition, altitudes in different types of triangles, formulae, some solved examples, and a few interactive questions for you to test your understanding.
CK-12 Foundation
Ck 12: Elem Math: Determine Unknown Angles: Isosceles, Scalene, Right Triangles
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on finding the missing angles in triangles.
CK-12 Foundation
Ck 12: Geometry: 45 45 90 Right Triangles
[Free Registration/Login may be required to access all resource tools.] Apply the special properties of 45-45-90 right triangles.
CK-12 Foundation
Ck 12: Geometry: Recognize 45 45 90 Right Triangles
[Free Registration/Login may be required to access all resource tools.] Recognize special right triangles and their properties.
CK-12 Foundation
Ck 12: Elem Math: Classifying All Types of Triangles by Lengths of Sides
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying triangles based on length of sides.
CK-12 Foundation
Ck 12: Elem Math: Classifying Triangles by Identifying the Number of Equal Sides
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying triangles based on the number of equal sides.
Math Is Fun
Math Is Fun: Right Angled Triangles
The resource investigates right triangle. Topics explored are isosceles, scalene, and 3,4,5 triangles. Examples, illustrations, and definitions are included.
Math Open Reference
Math Open Reference: Triangles
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
CK-12 Foundation
Ck 12: Trigonometry: Lengths of Sides in Isosceles Right Triangles
[Free Registration/Login may be required to access all resource tools.] Here you'll learn what an isosceles right triangle is, the relationships between the sides of an isosceles right triangle, and how to find the length of an unknown...
Lawrence Hall of Science
The Math Page: Trigonometry: The Isosceles Right Triangle
Here is a site that clearly and thoroughly explains the trigonometry of a 45-45-90 right triangle. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to...
CK-12 Foundation
Ck 12: Elem Math: Classifying Triangles Within Composite Figures
[Free Registration/Login may be required to access all resource tools.] In this learning module, students are presented with a composite figure and must identify the types of triangles within it. An accompanying video demonstrates a...
BBC
Bbc: Bitesize: Maths: 2 D Shapes
Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.
E-learning for Kids
E Learning for Kids: Math: Riksjas, Toek Toek: Polygons
Explore polygons with Wang, a ricksha puller. Answer his questions and he will give you a free ride!