Title: Learn to classify triangles by their side lengths and angle measures.
1Learn to classify triangles by their side lengths
and angle measures.
2Insert Lesson Title Here
Vocabulary
scalene triangle isosceles triangle equilateral
triangle acute triangle obtuse triangle right
triangle
3One way to classify triangles is by the lengths
of their sides.
Triangles classified by sides
A scalene triangle has no congruent sides.
4One way to classify triangles is by the lengths
of their sides.
Triangles classified by sides
An isosceles triangle has at least 2 congruent
sides
5One way to classify triangles is by the lengths
of their sides.
Triangles classified by sides
In an equilateral triangle, all of the sides are
congruent.
6One way to classify triangles is by the lengths
of their sides. Another way is by the measures of
their angles.
Triangles classified by angles
In an acute triangle, all of the angles are acute.
7One way to classify triangles is by the lengths
of their sides. Another way is by the measures of
their angles.
Triangles classified by angles
An obtuse triangle has one obtuse angle.
8One way to classify triangles is by the lengths
of their sides. Another way is by the measures of
their angles.
Triangles classified by angles
A right triangle has one right angle.
9Additional Example 1 Classifying Triangles
Classify each triangle according to its sides and
angles.
A.
Two congruent sides
isosceles
acute
Three acute angles
This is an isosceles acute triangle.
B.
scalene
No congruent sides
right
One right angle
This is a scalene right triangle.
10Additional Example 1 Classifying Triangles
Classify each triangle according to its sides and
angles.
equilateral
C.
Three congruent sides
acute
Three acute angles
This is a equilateral acute triangle.
D.
No congruent sides
scalene
right
One right angle
This is a scalene right triangle.
11Insert Lesson Title Here
Check It Out Example 1
Classify each triangle according to its sides and
angles.
isosceles
A.
Two congruent sides
obtuse
One obtuse angle
This is an isosceles obtuse triangle.
Two congruent sides
B.
isosceles
right
One right angle
This is an isosceles right triangle.
12Insert Lesson Title Here
Check It Out Example 1
Classify each triangle according to its sides and
angles.
scalene
C.
No congruent sides
obtuse
One angle exceeding 90
This is a scalene obtuse triangle.
D.
No congruent sides
scalene
obtuse
One angle exceeding 90
This is a scalene obtuse triangle.