Beacon Lesson Plan Library

What's Your Angle?

Cindy Jacobs


After reading the story [Magic Schoolbus Inside the Human Body] students form right, acute, and obtuse angles using the joints inside their bodies.


The student knows right angles (90 degrees).

The student solves real-world problems involving measurement using concrete and pictorial models for the following: length (for example, half-inch, centimeter); weight (for example, pound, kilogram); time (fifteen-, five-, and on-minute intervals); capacity (for example, cup, liter); temperature (Fahrenheit and Celsius); angles (right).


- Cole, Joanna. [Magic Schoolbus Inside the Human Body].
- Sheet of Paper
- Index Cards
- Chalk
- Pipe Cleaners (One Per Student)


1. Gather materials needed. You may wish to read the story in advance to shorten the lesson.


1. Read the book to the class.

2. Discuss with students that Ms. Frizzle's class went on a field trip to look at parts of the human body and how these parts worked. Today, we are going to talk about the parts of our bodies known as the joints.

3. Explain to students that joints are a very important part of our bodies because they allow our bodies to move and bend. Joints even help us bend our bodies at different angles.Allow students time to stand and bend various parts of their bodies to observe their joints at work such as the knees, shoulder, elbow, etc.

4.Next, hold up a sheet of paper and point to the corner. Tell students that the corner is a right angle. A right angle is where two sides of a square meet. A right angle is 90 degrees.You may want to have students look around the classrooom and identify objects with right angles.

5. Explain that an acute angle is anything less than a right angle. Therefore, it is less than 90 degrees. An obtuse angle, is wider than a right angle, therefore, it is greater than 90 degrees.

6. Next, with the students still standing have them bend their elbow joints, finger joints (index finger), and knee joints to form a right, acute, and obtuse angles. Talk about whether each angle is 90 degrees, less than 90 degrees, or greater than 90 degrees.

7. To reinforce and review, pass out a pipe cleaner to each student. Tell them to first bend it to make a right angle. Ask them how many degrees a right angle has? Next, have them bend it to make an acute angle. Ask them if it is less or greater than 90 degrees? Last, have them bend it to make an obtuse angle. Ask them whether it is less or greater than 90 degrees?

7. Last, give students an index card. Tell them to draw, label, and write a short description about a right, acute, and obtuse angle on the index card. Take up these cards for assessment purposes.


1. Mastery or non mastery will be based on two things (A) Informal observation of student performances while bending various parts of their bodies to form right, acute, and obtuse angles.(B) Student should identify, label, and describe each angle on their index cards with 80% accuracy.


Students could write a brief summary about what they learned about angles as a review the following day in a math journal or on a sheet of paper.
Return to the Beacon Lesson Plan Library.