Triangle classification by side lengths means comparing the three side measures: an equilateral triangle has three equal sides, an isosceles triangle has exactly two equal sides, and a scalene triangle has three different side lengths. The learner interprets these categories from diagrams or numerical measures and understands that this classification concerns side equality, not angle size; triangle inequalities and combined side-and-angle classifications are outside this scope.
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Detailed Explanation: Classify triangles by side lengths
To classify a triangle by its side lengths, compare the lengths of all three sides.
- Equilateral: all 3 sides are equal.
- Isosceles: exactly 2 sides are equal.
- Scalene: all 3 sides are different.
Example
A triangle has side lengths , , and . What type of triangle is it?
- List the side lengths: , , and .
- Compare them:
- The two sides measuring are equal.
- The side measuring is different.
- Exactly two sides are equal.
Therefore, the triangle is isosceles.
Remember: This classification looks only at the side lengths, not at the angles.
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Triangle Classification - Sides
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This Worksheet Includes:
- Triangle Classification - Sides
- Triangle Classification - Sides - Image to Description
- Triangle Classification - Sides - Name to Description
- Triangle Classification - Sides - Description to Name
- Triangle Classification - Sides - First Time
- Triangle Classification - Sides - Reversed
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