Triangle Adventures: Exploring Shapes and Angles!

Mathematics Grades 4th Grade 1:54 Video
Print Lesson Plan Watch Video

Lesson Description

Learn all about different types of triangles based on their sides and angles in this fun and engaging lesson!

Video Resource

Triangle Song | Types of Triangles Song | Classifying Triangles

Math Songs by NUMBEROCK

Duration: 1:54
Watch on YouTube

Key Concepts

  • Classifying triangles by their sides (scalene, isosceles, equilateral)
  • Classifying triangles by their angles (acute, obtuse, right)
  • The sum of angles in any triangle is 180 degrees

Learning Objectives

  • Students will be able to identify and classify triangles as scalene, isosceles, or equilateral based on their side lengths.
  • Students will be able to identify and classify triangles as acute, obtuse, or right based on their angles.
  • Students will be able to recognize that the sum of angles in any triangle is 180 degrees.

Educator Instructions

  • Introduction (5 mins)
    Begin by asking students what they already know about triangles. Show different real-world examples of triangles (e.g., pizza slice, road sign). Introduce the video and explain that it will help them learn about different types of triangles.
  • Video Viewing (5 mins)
    Play the NUMBEROCK "Triangle Song | Types of Triangles Song | Classifying Triangles" video. Encourage students to sing along and pay attention to the different types of triangles mentioned.
  • Discussion (10 mins)
    After the video, have a class discussion about the different types of triangles. Use visuals (drawings or physical models) to illustrate each type. Ask students to provide their own real-world examples of each type of triangle.
  • Activity: Triangle Sort (15 mins)
    Provide students with a set of pre-cut triangles (various shapes and sizes). Have them sort the triangles into categories based on their sides (scalene, isosceles, equilateral) and angles (acute, obtuse, right). Students can work individually or in small groups.
  • Wrap-up (5 mins)
    Review the different types of triangles and their characteristics. Answer any remaining questions. Preview the quiz that will follow.

Interactive Exercises

  • Triangle Drawing
    Have students draw their own examples of each type of triangle. They should label the sides and angles to show their understanding.
  • Triangle Hunt
    Give students a scavenger hunt to find examples of different types of triangles in the classroom or around the school.

Discussion Questions

  • What are some real-world examples of triangles you see every day?
  • How can you tell the difference between a scalene, isosceles, and equilateral triangle?
  • How can you tell the difference between an acute, obtuse, and right triangle?
  • Why do you think it's important to be able to classify triangles?
  • What is the relationship between the sides and angles of a triangle?

Skills Developed

  • Classification
  • Observation
  • Critical Thinking
  • Geometry
  • Visualization

Multiple Choice Questions

Question 1:

A triangle with all three sides equal is called:

Correct Answer: Equilateral

Question 2:

A triangle with a 90-degree angle is called:

Correct Answer: Right

Question 3:

A triangle with no equal sides is called:

Correct Answer: Scalene

Question 4:

An isosceles triangle has how many equal sides?

Correct Answer: Two

Question 5:

An acute triangle has all angles less than:

Correct Answer: 90 degrees

Question 6:

What is the sum of angles inside of a triangle?

Correct Answer: 180 degrees

Question 7:

If a triangle has one angle greater than 90 degrees, it is a(n) _____ triangle.

Correct Answer: Obtuse

Question 8:

Which of these is NOT a type of triangle based on its sides?

Correct Answer: Obtuse

Question 9:

Which type of triangle can also be a right triangle?

Correct Answer: Scalene

Question 10:

A road sign shaped like a triangle with all equal sides is what type of triangle?

Correct Answer: Equilateral

Fill in the Blank Questions

Question 1:

A triangle with two equal sides is called an ______ triangle.

Correct Answer: isosceles

Question 2:

A __________ triangle has one angle that is exactly 90 degrees.

Correct Answer: right

Question 3:

A triangle with three unequal sides is called a __________ triangle.

Correct Answer: scalene

Question 4:

A triangle with all three angles less than 90 degrees is called an ___________ triangle.

Correct Answer: acute

Question 5:

A triangle with one angle greater than 90 degrees is called an ________ triangle.

Correct Answer: obtuse

Question 6:

An equilateral triangle has ______ equal sides.

Correct Answer: three

Question 7:

The angles inside of a triangle always add up to ______ degrees.

Correct Answer: 180

Question 8:

A skateboard ramp can be shaped like a _________ triangle.

Correct Answer: right

Question 9:

Mountain climbing, as shown in the video, can illustrate a(n) __________ triangle.

Correct Answer: isosceles

Question 10:

If all three sides of a triangle are the same length, it is also a(n) __________ triangle.

Correct Answer: equilateral

Educational Standards

4.GM.1:Name, describe, classify, and construct polygons and three-dimensional figures based on their attributes; recognize polygons and three-dimensional figures in real-life and mathematical situations. 4.GM.1.1:Identify points, lines, line segments, rays, angles, endpoints, and parallel and perpendicular lines in various models.

Teaching Materials

Download ready-to-use materials for this lesson:

Student Worksheet Classroom Slides Assessment Quiz
Add to Google Classroom

User Actions

Sign in to save this lesson plan to your favorites.

Sign In

Share This Lesson

Related Lesson Plans