Classifying Triangles by Sides

In this video, fourth graders learn to classify triangles by their sides: equilateral, isosceles, and scalene. Equilateral triangles have three equal sides, isosceles have two, and scalene have none. The video also revisits classifying triangles by angles: acute, obtuse, and right. Students practice identifying triangle types and learn that a right equilateral triangle is impossible. The lesson combines knowledge of angles and sides to deepen understanding of triangle classification.

What type of triangle has three equal sides?

• Right

• Isosceles

• Equilateral

• Scalene

What does the term 'equilateral' imply about the triangle's sides?

• One right angle

• All sides are equal

• No equal sides

• Two equal sides

What does 'equilateral' mean in the context of triangles?

• Unequal sides

• Equal sides

• Equal angles

• Two equal sides

Which triangle has two sides of the same length?

• Acute

• Isosceles

• Equilateral

• Scalene

Which triangle is named after a word meaning 'equal legs'?

• Right

• Isosceles

• Scalene

• Equilateral

What type of triangle has exactly two equal sides?

• Right

• Scalene

• Equilateral

• Isosceles

What is unique about scalene triangles?

• Two sides are equal

• All sides are equal

• No sides are equal

• One right angle

What term is used for triangles with all sides of different lengths?

• Equilateral

• Isosceles

• Scalene

• Acute

Which triangle has no equal sides and no equal angles?

• Right

• Scalene

• Equilateral

• Isosceles

Can a triangle be both right and equilateral?

• Only in non-Euclidean geometry

• No

• Only if it has two right angles

• Yes