Soft Schools
Soft Schools: Types of Triangles Quiz
The problems on this quiz give descriptions and properties of specific triangles. Students are expected to read the information and identify the triangle that is being described.
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.
CK-12 Foundation
Ck 12: Elem Math: Determining the Length of an Unknown Side of a Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video tutorial and attempt practice problems on how to determine the unknown side length of a triangle.
CK-12 Foundation
Ck 12: Elem Math: Determining the Unknown Angle in an Isosceles Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on finding the missing angle in an isosceles triangle.
CK-12 Foundation
Ck 12: Elem Math: Determining the Unknown Angle in a Right Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on finding a missing angle in a right triangle.
CK-12 Foundation
Ck 12: Elem Math: Determining the Unknown Angle in a Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to determine a missing angle in a triangle.
CK-12 Foundation
Ck 12: Elem Math: Determining Unknown Angles in Complex Composite Figures
[Free Registration/Login may be required to access all resource tools.] Students watch a video and take an assessment on finding missing angles in composite figures.
CK-12 Foundation
Ck 12: Elem Math: Determining Unknown Angles in Composite Figures
[Free Registration/Login may be required to access all resource tools.] Students watch a video and take an assessment on finding missing angles in a polygon.
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: Elem Math: Determining Unknown Angles in Parallelograms
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to determine missing angles in a parallelogram.
CK-12 Foundation
Ck 12: Elem Math: Determining Unknown Angles Within Rectangles and Squares
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to determine missing angles within rectangles and squares.
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.
University of Cambridge
University of Cambridge: Nrich: Triangles to Tetrahedra
Given an unlimited number of a specific type of equilateral, isosceles, and right triangles create as many tetrahedra as are possible. Includes printout.
Merriam-Webster
Merriam Webster: Dictionary Illustration: Types of Triangles
A labeled illustration of six different types of triangles.
Other
Visnos: Polygons
Create regular and irregular polygons and determine the angles and side lengths with this interactive exercise. Use Safari or Chrome browser.
Khan Academy
Khan Academy: Classify Shapes by Line and Angle Types
Classify shapes based on pictures or attributes, such as angle types and side-lengths. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Identify Triangles by Angles
Practice identifying triangles by their angles as acute, right, or obtuse. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Identify Triangles by Side Lengths
Practice identifying triangles by their side-lengths as equilateral, isosceles, or scalene. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Illustrative Mathematics
Illustrative Mathematics: 4.g What Is a Trapezoid? (Part 1)
The purpose of this task is for students to articulate a definition for a trapezoid. Aligns with 4.G.A.2.
Illustrative Mathematics
Illustrative Mathematics: 4.g What Shape Am I?
In this task, students ultimately use the definitions they are given for three types of quadrilaterals and what they know about parallel sides to identify that a square fits all the definitions and explain why. Aligns with 4.G.A.2.
Illustrative Mathematics
Illustrative Mathematics: 4.g Are These Right?
The purpose of this task is for students to measure angles and decide whether the triangles are right or not. Aligns with 4.G.A.2.
Illustrative Mathematics
Illustrative Mathematics: 4.g Lines of Symmetry for Triangles
The division of triangles into scalene, isosceles, and equilateral can be thought of in terms of lines of symmetry. Aligns with 4.G.A.3.
Illustrative Mathematics
Illustrative Mathematics: 4.md,g Finding an Unknown Angle
The purpose of this task is to give 4th grade students a problem involving an unknown quantity that has a clear visual representation. Aligns with 4.G.A.2.