This document defines and describes the three types of triangles: equilateral, isosceles, and scalene. Equilateral triangles have three sides of equal length, isosceles triangles have two equal sides, and scalene triangles have no equal sides. The document explains that triangles can be identified by comparing the lengths of their sides, whether labeled with numbers or indicated by dashes, and categorized based on how many sides are the same length.
2. Triangles can be identified by the length of their sides
● Equilateral Triangle
○ All sides are the same length or EQUAL
○ This triangle is ALWAYS acute
○ Also called a Regular Triangle
3. Triangles can be identified by the length of their sides
● Isosceles Triangle
○ Two sides are the same length
○ Is often tall and skinny like the letter I
4. Triangles can be identified by the length of their sides
● Scalene Triangle
○ No are the same length (all sides are different)
○ Looks like it is LEANING over
5. So how do you tell what kind of triangle it is?
● Look at the length of the sides
○ If the sides are already labeled, look at how many
sides are the same.
○ No sides the same, Scalene
2 sides the same, Isosceles
3 sides the same, Equilateral
6. Now you try.
● Look at the length of the sides
○ No sides the same, Scalene
2 sides the same, Isosceles
3 sides the same, Equilateral
7. What if the sides aren’t labeled?
● Look at the length of the sides
○ The side lengths will be noted by little dashes.
○ Count the number of dashes. The same number of
dashes means the same length.
