Lesson 11 Use a Protractor to Draw Angles
Let’s draw some angles.
Warm-up Estimation Exploration: Long Hand and Short Hand
How many degrees is the angle formed by the long hand and the short hand of the clock?
Make an estimate that is:
too low | about right | too high |
---|---|---|
Activity 1 Draw These Angles
Draw a line that is neither vertical nor horizontal. Put a point somewhere on that line. Use your protractor to draw a perpendicular line through that point. Be as precise as possible. (No folding this time!)
Here is a ray that starts at point
. Use a protractor to draw:
A ray starting at point
to create a angle. Another ray starting at point
to create a angle. One more ray starting at point
to create a angle. Label each angle with its measurement.
In your drawing, there should be one angle that is not labeled with a measurement and is larger than
. Label the angle with an arc. How many degrees is this angle? Be prepared to explain how you know.
Activity 2 Angles Made to Order
Your teacher will give you some blank cards. Label them a–d.
On each card, draw an angle that meets one requirement. Use a ruler and a protractor.
an angle that is less than
an angle that is between
and an angle that is greater than
but less than an angle that is greater than
but less than
Trade cards with your partner.
Measure and record each angle your partner drew. Check to make sure each angle meets the requirement.
If a requirement is not met, return it to your partner so it can be corrected. Save the cards for the next lesson.
If you have time… If you have time:
Create a drawing that shows several angles. Then, write some descriptions of your drawing. Be as specific as possible.
Ask a partner to recreate the drawing based on your descriptions. Does their drawing turn out as you had drawn? If not, adjust your descriptions and ask them to try again.
Practice Problem
Problem 1
Draw a ray. How many different