Curated OER
Triangles
In this triangle worksheet, middle schoolers identify triangles according to the characteristics of their sides. Students identify scalene, isosceles, equilateral and right triangles. Eleven triangle problems are provided in this...
Curated OER
Indirect Euclidean Proofs
In this Euclidean proofs worksheet, 10th graders solve 10 different problems that include completing indirect Euclidean proofs. First, they write a statement for each of the reasons listed on the sheet of proofs. Then, students solve the...
Curated OER
Classifying Triangles
In this classifying triangles worksheet, 10th graders solve 12 different problems that include classifying various types of triangles. They classify and then identify each of the given triangles as isosceles, scalene, or equilateral....
Curated OER
Classifying Triangles
In this classifying triangles instructional activity, 10th graders solve 6 different problems related to the classification of triangles either by their angles or by their sides. First, they use a protractor and a ruler to draw triangles...
Curated OER
Types of Triangles
As a reference sheet for types of triangles, this worksheet would be good for students to keep in their binder or to take notes about; however, it would need to accompany an existing lesson as there is no activity beyond basic...
Curated OER
Triangle Puzzler
Students are introduced to some basic concepts of geometry. They explain that the definition of a triangle is a figure with three sides, three angles, and three points. Triangles can be named by using three points in their correct sequence.
Curated OER
Triangle Challenge
In this triangles activity, students identify and name 3 different types of triangles. First, they determine the number of right triangles in the figure shown on the sheet. Then, students determine the number of equilateral triangles and...
Curated OER
Triangle Angle Sort
In this triangle and angle worksheet, 10th graders identify 36 different angles and triangles illustrated on the sheet. First, they define the vocabulary to include equilateral, scalene, right, and isosceles triangle. In addition, they...
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.
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...
Math Is Fun
Math Is Fun: Interactive Triangles
This is an excellent tool for students to explore how changes in the size of a triangle's sides or angles affect its appearance. Different types of triangles and angles are presented.
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.
OER Commons
Oer Commons: Classifying Triangles
In this lesson, students learn to classify triangles by the size of the angles and the measures of the sides. Students will use interactives to explore equilateral, isosceles, scalene, acute, obtuse, and right triangles. Included are...
The Math League
The Math League: Scalene Triangle
This site provides the definition of Scalene triangles.
ClassFlow
Class Flow: Angle Facts
[Free Registration/Login Required] This lesson is a thorough review of all types of angles (e.g. obtuse, right, scalene, isosceles, equilateral, alternate) with wonderful diagrams to reinforce thinking skills.
ClassFlow
Class Flow: Braun Shapes
[Free Registration/Login Required] This lesson is an in depth review of finding many shapes, their properties, and reinforcing first flipchart- Braun.
Wolfram Research
Wolfram Math World: Scalene Triangles
MathWorld gives a brief definition of scalene triangles and then lists links to related topics and terms.