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Triangles

This topic covers the classification of triangles by their side lengths and angle measures. We also use the sum of the measures of the angles of a triangle to solve problems.

Topic: Classifying Triangles

  • A scalene triangle has no congruent sides. An isosceles triangle has at least two congruent sides. An equilateral triangle has three congruent sides

  • An acute triangle has only acute angles (less than 90°).
    An obtuse triangle has exactly one obtuse angle (more than 90°).
    A right triangle has one right angle (equal to 90°)

Topic: Find the Unknown Angle

  • A triangle is a closed figure with three line segments and three angles

  • The sum of the measures of the angles in any triangle is 180°. We can use this to find the unknown angle measures
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