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Learning Resource Type

Lesson Plan

Wanted: Angles of All Sizes!

Subject Area

Digital Literacy and Computer Science




In this lesson, students will explore straight, right, acute, and obtuse angles. Students will go to the playground to search for angles. The students will use digital cameras to record their findings. They will use their findings to create a slideshow to present to the class.

    Mathematics (2019) Grade(s): 4


    Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines, and identify these in two-dimensional figures.

    Unpacked Content



    • Point
    • Line
    • Line segment
    • Ray
    • Right angle
    • Acute angle
    • Obtuse angle
    • Perpendicular lines
    • Parallel lines
    • Two dimensional figure
    • Vertex
    • Angle measure


    Students know:
    • defining characteristics of geometric figures, such as points, lines, line segments, angles (right, acute, and obtuse), parallel lines, and perpendicular lines.


    Students are able to:
    • Draw points, lines, line segments, rays, angles (right, acute, obtuse).
    • Draw parallel and perpendicular lines.
    • Identify points, lines, line segments, rays, angles, parallel lines, and perpendicular lines in two-dimensional figures.


    Students understand that:
    • points, lines, line segments, angles (right, acute, and obtuse), parallel lines, and perpendicular lines are defining characteristics of two dimensional shapes.

    Primary Learning Objectives

    Students will be able to work collaboratively to identify straight, right, obtuse, and acute angles. 


    Before Activity

    Engage the students by asking them to look around the classroom and identify four angles. The students will discuss their angles with their tables. Students should discuss if the angles are larger or smaller than 90 degrees. Call the class together and allow each table to share their favorite findings. If the students are not accurately describing straight, right, acute, and obtuse angles, then reteach the definitions of each and give visual examples throughout the room. This engagement should only last 10-15 minutes.

    During Activity

    Students will explore and identify more straight, acute, obtuse, and right angles by going outside to search for these angles on the playground. They will use the My Angles Drawing Handout to record their findings. Students will use digital cameras to take pictures of where they locate each angle. Students must identify and take a picture of each type of angle. Allow 15-20 minutes for this exploration.

    After Activity

    Bring the class back together. Each cooperative group of students will use their recordings on the digital cameras to create a slideshow presentation. On the slideshow presentation, each group must identify the type of angle on each picture. They must also explain how they know that it is right, straight, acute, or obtuse angle. This part of the lesson could be done in the computer lab. Students are encouraged to be creative as they create their slideshow. Students may save and submit their work using the teacher's preferred method. Allow 60-75 minutes for this part of the lesson.

    Allow each group to present/communicate their findings to the class.

    Assessment Strategies

    Students will be assessed on their presentation to the class. They will be assessed on whether they correctly captured and identified the four types of angles.


    Approximate Duration

    Total Duration

    Greater than 120 Minutes

    Background and Preparation


    Teacher prep: Students need to be put into cooperative groups of four before starting this activity. The teacher should have a digital camera and an angles worksheet available for each group.

    Student prep: Students should have basic knowledge of the definition of a straight, right, acute, and obtuse angle. Students should have prior knowledge of creating a slideshow using images from digital camera. Students should also be aware of the rules of working in collaborative groups.

    Materials and Resources

    Materials and Resources

    Per Group: My Angles Drawings Handout, Pencils

    Technology Resources Needed

    Per Group: digital camera (or alternative), computer (with slideshow software), Interactive Board or Projector, flash drive