Classifying Triangles by Sides and Angles

In this video, Mr. J teaches fifth-grade students how to classify triangles by their sides and angles. The video covers the definitions and characteristics of scalene, equilateral, and isosceles triangles based on side lengths, as well as right, obtuse, and acute triangles based on angle measures. The video concludes with a link to a mastery check video for further practice.

What does it mean if a triangle is classified as scalene?

• Two sides are of equal length.

• All sides are of equal length.

• No sides are of equal length.

• It has a right angle.

Tags

CCSS.4.G.A.2

Which statement is true for a scalene triangle?

• No sides are congruent.

• It has one 90 degree angle.

• All sides are congruent.

• It has two congruent sides.

Tags

CCSS.4.G.A.2

What type of triangle has all sides of the same length?

• Acute

• Equilateral

• Scalene

• Isosceles

Tags

CCSS.4.G.A.2

What is necessary for a triangle to be classified as equilateral?

• Two congruent sides

• All sides congruent

• One angle greater than 90 degrees

• One 90 degree angle

Tags

CCSS.4.G.A.2

Which triangle has two sides of equal length?

• Equilateral

• Scalene

• Isosceles

• Right

Tags

CCSS.4.G.A.2

What defines a right triangle?

• All sides are of equal length.

• One angle is more than 90 degrees.

• One angle is exactly 90 degrees.

• All angles are less than 90 degrees.

Tags

CCSS.4.G.A.2

What type of triangle has one angle greater than 90 degrees?

• Acute

• Equilateral

• Right

• Obtuse

Tags

CCSS.4.G.A.2

How is an acute triangle defined in terms of its angles?

• Two angles are less than 90 degrees.

• All angles are less than 90 degrees.

• One angle is greater than 90 degrees.

• All angles are exactly 90 degrees.

Tags

CCSS.4.G.A.2

What type of triangle has all angles less than 90 degrees?

• Right

• Isosceles

• Obtuse

• Acute

Tags

CCSS.4.G.A.2

If a triangle has a 40 degree, a 40 degree, and a 100 degree angle, what type of triangle is it?

• Obtuse

• Acute

• Right

• Equilateral

Tags

CCSS.4.G.A.2