Types of triangles and definitions. Acute triangle,obtuse triangle,right triangle, isosceles triangle, equilateral triangle, and scalene triangle.

1. Teacher: Ms. Begum
Grade: 6th
Subject: Mathematics

2. 1. Carlos said: “I know a way to pick out three points so you
don’t get a triangle. Take one point in the middle of the front
wall, another point in the ceiling, and a third point on a side
wall.” Was Carlos correct?

3. Types of Triangles
There are six types of triangles:
A Simple Mnemonic to assist with these
names is this: ROSE Is Amazing!
1. R - Right
2. O - Obtuse
3. S - Scalene
4. E - Equilateral
5. I - Isosceles
6. A - Acute

4. Right Triangle
Right triangle is a triangle that has
only one right angle. A right angle is
equal to 90°.

5. Equilateral triangle
An equilateral triangle has three
congruent sides and angles.

6. Isosceles triangle
An isosceles triangle has two congruent
sides and angles.

7. Scalene triangle
Scalene triangle has no congruent sides
or angles.

8. Obtuse triangle
An obtuse triangle has only one obtuse
angle. An obtuse angle is greater than 90°
degrees and less than 180° degrees.

9. Acute triangle
An acute triangle has three acute angles.
An acute angle is less than 90°.

10. The End