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Math Example--Polygons--Triangle Classification: Example 7
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Geometry >> Triangles >> Definition of a Triangle

Math Example--Polygons--Triangle Classification: Example 7

Math Example--Polygons--Triangle Classification: Example 7

A triangle with angles labeled 20°, 50°, and x.

Topic

Triangles

Description

This example presents a triangle with two known angles, 20° and 50°, and an unknown angle x. Solving for x, we find it to be 110°. Since one angle is greater than 90°, the triangle is classified as obtuse.

Triangles can be classified by their angles, where obtuse triangles have one angle over 90°. Reviewing examples like this aids students in understanding classification based on angle measures.

Seeing multiple examples reinforces the rules and helps students apply classification consistently and accurately.

Teacher's Script: "By calculating the missing angle, we see that one angle is more than 90°, making this an obtuse triangle. Angle sizes guide our classification."

For a complete collection of math examples related to Triangles, click on this link: Math Examples: Triangle Classification Collection.

Common Core Standards CCSS.MATH.CONTENT.7.G.A.2, CCSS.MATH.CONTENT.4.G.A.2, CCSS.MATH.CONTENT.5.G.B.3
Grade Range 4 - 7
Curriculum Nodes Geometry
    • Triangles
        • Definition of a Triangle
Copyright Year 2013
Keywords triangles, classification