# Triangles

Learn and practice identifying and classifying triangles with interactive resources from GeoGebra.

## Upper Elementary

GRADES 4-5

### Types of Triangles

Identify and classify triangles according to the measures of the interior angles and the lengths of the sides; relate triangles based upon their hierarchical attributes.

## Middle School

GRADES 6-8

### Angle Sum Properties of Triangles, Quadrilaterals, and Polygons

Use a variety of triangles, quadrilaterals, and other polygons to draw conclusions about the sum of the measures of the interior angles.

### Similar Triangles and Correspondence

Use properties of triangles to solve problems related to similar triangles and the relationships of their corresponding parts.

### Triangle Inequality Theorem

Recognize conditions of side lengths that determine a unique triangle, more than one triangle, or no triangle.

### Related Topics

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