Download Classifying Triangles

Classifying Triangles
Ms. Gardner
What is a Triangle?
• A Triangle is a THREE SIDED polygon.
• Last class we classified ANGLES as acute
(skinny), right (middle), and obtuse (fat).
Guess what? We can classify TRIANGLES the
same way!
Classifying Triangles by Angle
Measurements:
• There are three different types of triangles
based on their angles. Are the angles in the
triangle SKINNY or FAT?
• The three types of triangles are:
1. Acute Triangle
2. Right Triangle
3. Obtuse Triangle
Acute Triangle
• All three angle measures are acute angles
(skinny/baby). An acute angle measures LESS
THAN 90 DEGREES.
Right Triangle
• One angle is a right angle. A right angle
measures EXACTLY 90 DEGREES.
Obtuse Triangle
• One angle is an obtuse angle (old, fat). Obtuse
angles measure GREATER THAN 90 DEGREES,
but LESS THAN 180 DEGREES.
How “old” is a Triangle?
• Just like we said that a STRAIGHT LINE is 180
degrees (180 years old), a TRIANGLE is 180
degrees as well!
• Example
Classifying Triangles by the length of
their sides:
• We can classify triangles by how long their
sides are.
• Three types of triangles:
1. Equilateral
2. Isosceles
3. Scalene
Equilateral Triangles
• ALL sides are the same length.
Isosceles Triangles
• TWO sides are the same length.
Scalene Triangle
• NO sides are the same length.