All About Angles
Students will learn the characteristics of 4 different angles and use this information to identify and draw the angles.
- Tell students that today they will be learning about 4 different types of angles.
- Begin your presentation with a right angle. Demonstrate how a right angle measures 90 degrees with a protractor. Ask students to name some items in the room with a right angle. Example: the corner of a book, the corner on the window.
- Introduce the other angles by referring to and comparing them to the right angle.
- Tell students that an acute angle is smaller than a right angle, or under 90 degrees, and that an obtuse angle is wider than a right angle, or greater than 90 degrees.
- Tell students that when an angle measures exactly 180 degrees, it just looks like a straight line and is referred to as a straight angle.
- Create an anchor chart with the 4 angles that lists their characteristics. Ask the students to help you create a T-chart on the whiteboard or the document camera and write down how the angles are similar and how they are different.
- Discuss and check for understanding.
Explicit Instruction/Teacher modeling(10 minutes)
- In this session you will use a kinesthetic strategy to reinforce the names of the angles and their measurements.
- Tell the students that they will be demonstrating the different angles that you just discussed by using their arms.
- Ask everyone to stand up and leave an arms distance between each other.
- Tell them their bodies will be the vertex, or the point of the angle, and their arms will represent the angle's rays.
- Demonstrate each angle with your arms and ask the children to name each of the angles.
- Tell the students that they will now make the angle with their arms when you say the angle’s name.
- Call out the different angles and observe students to check for understanding. Repeat several times until students appear to consistently demonstrate the angles correctly.
Guided Practice(25 minutes)
- Students will now participate in a hands-on activity in which they will create their own angle poster using toothpicks to represent the four types of angles.
- Prior to this activity with the students, create your own poster to provide an example for the students.
- Pass out the toothpicks, glue, construction paper, and markers.
- Display your poster and explain how they will use toothpicks to create the four types of angles on construction paper.
- The toothpicks should be glued down and be a correct representation of the angle.
- Tell students that they will use a marker to write the title for the poster and label all the angles.
- Encourage students to make colorful and creative posters.
- Check for understanding and accuracy as the students create their posters.
Independent working time(10 minutes)
- Students will complete their toothpick posters independently.
- Walk around as they work and provide verbal feedback.
- Encourage students to create colorful and creative posters.
- After completion of the activity, collect the posters to have items for a great bulletin board display.
- Enrichment: Students who are advanced with this math skill could work in a small group with the teacher during math center time. The teacher can introduce them to the use of a protector. After demonstrating and practicing, require these students to not only identify the type of angle on practice sheets but additionally write the number of degrees measured by their protractor for the angle.
- Support: Work with any students you have observed during guided modeling that appeared to be struggling with the activity. Review their toothpick poster and make any needed revisions with the student.
- During all activities informally assess the mastery of the math concepts you are teaching.
- As an exit ticket, ask students to take out a piece of notebook paper and then name each of the 4 angles and ask them to draw and label the angles.
- Collect exit slips and posters.
- Review and return exit slips to students and note any students who may need further review.
Review and closing(10 minutes)
- Toothpick posters should be displayed in the classroom.
- Discuss posters and math concepts.
- Discuss techniques used on the poster that made it visually attractive and interesting.