Types of Triangles

In this lesson, you'll learn about the three classifications of triangles based on angles and sides: acute, obtuse, and right triangles and scaling, isosceles, and equilateral triangles. You'll also learn how to solve problems using this knowledge, such as finding the length of sides in triangles based on coordinate points and determining whether a triangle is isosceles or equilateral.

Learn all about triangles -- their classifications and properties, and how to solve problems with this knowledge.

• What is the difference between a right, acute, and obtuse triangle?
• What is the difference between a scalene, isosceles, and equilateral triangle?
• What does x equal if three sides of an equilateral triangle are x + 9, 2x, and 3x - 9?
• If a triangle has vertices at (2, 2), (3, 9), and (-5, 3), is the triangle scalene, isosceles, or equilateral?
• How can you determine if a triangle is scalene, isosceles, or equilateral?