Page 873 - Algebra 1

Classify Angles and Triangles
Skills Bank Lesson 13
You can classify an angle by its measure.
Classification of Angles
An acute angle measures less than 90°.
A right angle measures exactly 90°.
An obtuse angle measures more than 90° and less than 180°.
A straight angle measures exactly 180°.
You can classify a triangle by its angle measures.
Classification of Triangles by Angle Measures
An acute triangle has three acute angles.
An equiangular triangle has three congruent acute angles.
A right triangle has one right angle.
An obtuse triangle has one obtuse angle.
You can also classify a triangle by its side lengths.
Classification of Triangles by Side Lengths
An equilateral triangle has An isosceles triangle has at A scalene triangle has no three congruent sides. least two congruent sides. congruent sides.
858 Saxon Algebra 1