What’s Your Angle?

Lesson Plan - Get It!

Audio:

This lesson will help you refresh your angle-measurement math skill.

Before you review the activity below, or complete any of the activities included in this lesson, take a moment to define the following vocabulary (You can access A Maths Dictionary for Kids Quick Reference for assistance defining the vocabulary words below or checking for accuracy once you define the words.):

• acute angle
• complementary angle
• endpoint
• line
• line segment
• obtuse angle
• protractor
• ray
• right angle
• straight angle
• supplementary angle
• vertex

Refresh your memory

Angles, angles, everywhere! Our lives are full of angles. You can look just about anywhere in your daily environment and find numerous examples of angles. For this skill-sharpening lesson of angle measurement, the example of a clock face will be used to help you review your knowledge of this skill and your ability to measure angles.

To have a hands-on tool to assist you, ask your parent or teacher if you can borrow an analog clock (See below):

Set the clock to reflect 3 o’clock (See below):

Take out your protractor to take the measurement of the angle you just made on the face of the clock. Remember to line up the hole in the protractor with the vertex of the angle and the 0° measurement on one of the two lines made by the hands of the clock (See below):

It may be difficult to see in this lesson, and hopefully it is easier to see using the clock and protractor in front of you, that the measurement of the clock hands, when set at 3 o’clock, is 90°. As long as you remember to place the hole of your protractor at the vertex of any given angle, and line up the 0° mark on the protractor with one of the rays, lines, or line segments of the angle, you will be able to use the other line of the angle to get the exact measurement of that angle.

Complete the activity below to make sure that you understand the math skill that you are sharpening.

Set your clock hands for the following times. Then, use your protractor to measure each of the angles (times) you set on the clock face. Check your answers below once you have measured them all:

• 2:15
• 6:55
• 1:28
• 10:45

The Got It? section offers two opportunities for you to continue to sharpen your angle measurement skills!