Page 70 - Math Course 3 (Book 2)

Identifying Triangles: Angles and Sides
Mo. 9

Lesson 1 equiangular triangle

An acute triangle with all angles congruent is an
equiangular triangle.

KEY CONCEPTS:

1. Identify and classify triangles by angles. 60°
2. Identify and classify triangles by sides.
3. Find the measures of the sides of a triangle.

MO. 9 - L1a 60° 60°

Classify Triangles by Angles
and Sides scalene triangle
No two sides of a scalene triangle are congruent.

Vocabulary A-Z

Let us learn some vocabulary

acute triangle
In an acute triangle, all of the angles are acute.

isosceles triangle
67° At least two sides of an isosceles triangle are

one angle measures < 90 congruent.

37° 76°

obtuse triangle
In an obtuse triangle, one angle is obtuse.

13°
one angle measures > 90 142° 25° equilateral triangle

All of the sides of an equilateral triangle are con-
gruent.
right triangle
In a right triangle, one angle is a right angle.

42°

all angle measures = 90

90° 48°

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