Interior Angles of a Quadrilateral Experiment

A QUADRILATERAL is a polygon with 4 sides and 4 angles.

Different types of quadrilaterals are parallelograms, rectangles, squares, rhombuses, and trapezoids.


In this experiment, students will predict the sum of all 4 interior angles of a particular quadrilateral. Then they will predict if the different kinds of  quadrilaterals have the same sum for their interior angles.

Materials

• paper
• pencil
• marker (optional)
• ruler
• protractor
• scissors

Directions

• Have students draw 3 different types of quadrilaterals and cut out each one.

• Mark each angle. Use a square for right angles and a curved line for all other angles.

• Have the student choose one of the quadrilaterals.
• Predict the sum of all 4 interior angles.
• Cut off the corners (angles) of the quadrilaterals.

• Place the cut pieces together with the angles touching each other.
• Observe!

• What is the sum of all 4 angles?
• Next predict if the answer will be the same for the other quadrilaterals.
• Repeat the steps above for the other quadrilaterals
• Was the prediction correct? What is the sum of the interior angles in a quadrilateral?

The sum of all the angles in a quadrilateral =  360 degrees. 


Extension Activity:

Try the above experiment with a pentagon, hexagon, and/or octagon.

Have fun with geometry!