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Activity 3.8
Assignment 3.12
Classifying Triangles: Congruent Sides
Objectives
Classify triangles by congruent sides as equilateral, isosceles, or scalene.
Name the base, legs, vertex, vertex angles, and base angles of isosceles triangles.
Assignment 3.9
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About Geometry Worksheet Assignment 3.12:
Assignment 3.12 is an introduction to classification of triangles by number of congruent sides.
Prerequisite Skills: Name line segments (Assignment 1.12). Identify pairs of congruent line segments (Assignment 1.15). Name angles (Assignment 2.4).
Definitions: A triangle with no pair of congruent sides is a scalene triangle.
A triangle with a pair of congruent sides is an isosceles triangle.
A triangle with all sides congruent is an equilateral triangle.
In an isosceles triangle:
the congruent sides are the legs. The other side is the base.
the angle with its vertex at the vertex of the triangle is the vertex angle.
the two angles with vertices a the endpoints of the base are the base angles.