Classifying Triangles in a Hierarchy

Mr. Kazu explains how to classify triangles using a hierarchy. He begins by introducing the concept of hierarchies with examples of students and food. He then defines polygons and focuses on triangles, describing their types based on side lengths: scalene, isosceles, and equilateral. Next, he categorizes triangles by angles: right, acute, and obtuse. Finally, he demonstrates how to classify triangles using examples and a hierarchy chart.

What is a hierarchy primarily used for?

• Sorting things by weight

• Sorting things by size

• Sorting things by importance or characteristics

• Sorting things by color

Which of the following is NOT a property of polygons?

• Made up of straight lines

• Enclosed figures

• Three-dimensional

• Flat figures

What distinguishes a scalene triangle?

• All angles are less than 90 degrees

• No sides are of equal length

• At least two sides are of equal length

• All sides are of equal length

Which type of triangle has at least two equal sides?

• Scalene

• Equilateral

• Acute

• Isosceles

What is a special type of isosceles triangle?

• Scalene

• Right

• Obtuse

• Equilateral

Which type of triangle has all interior angles less than 90 degrees?

• Equilateral triangle

• Acute triangle

• Obtuse triangle

• Right triangle

What angle measurement defines a right triangle?

• More than 90 degrees

• Less than 90 degrees

• 60 degrees

• Exactly 90 degrees

Which triangle classification can only be acute?

• Scalene

• Isosceles

• Equilateral

• Obtuse

In which triangle do all sides have the same length?

• Scalene

• Right

• Isosceles

• Equilateral

What type of triangle is formed when one angle is greater than 90 degrees?

• Acute

• Equilateral

• Right

• Obtuse