Constructing Angles

Summary
This lesson introduces the protractor and its uses, and children learn how to construct a 90 degree angle. Activity A reinforces their understanding of a protractor, and Activity B gives them practice in measuring and constructing 90 degree angles.

Objectives
• The children will be able to measure angles using a protractor.

• The children will be able to construct and name a 90 degree angle.

Suggested Grades
4th Grade
5th Grade

Excerpt
An angle is the place where 2 lines cross each other. Angles are everywhere! For example, there is an angle between the wall and the floor, and between your leg and your foot. How many angles can you find in the classroom?

When we measure lengths we use a ruler and measure in units of length such as centimeters. When we measure weights we use a scale and measure in units of weight such as grams. The units we use for measuring angles are called degrees and we use a protractor to measure them.

Continued...