1. 5-Minute Check
Draw a circle and label the radius with 4 meters. What is the length of the diameter?
Draw a circle and label the diameter with 12 inches. What is the radius?

2. Geometry: Congruent and Symmetry
By Mr. Bales

3. Objective
By the end of this lesson, you will be able to identify congruent figures and identify figures that have bilateral and rotational symmetry.
Standard 4MG3.3 - Students will identify congruent figures.
Standard 4 MG3.4 - Students will identify figures that have bilateral and rotational symmetry.

4. Introduce
Take a piece of paper and fold it in half and then in half again.
Trace a pattern block on top of the paper.
Cut out the figure through the four layers of paper.
How many figures are there?
Are all the figures the same size and shape?
How do you know?

5. Teach Take a look at these two pattern blocks. (parallelograms)
How are the two figures alike?
Watch as I rotate the blocks.
Are the two figures still alike?
Is it possible to have two triangles that are not congruent? Explain.
What can we do to be certain two figures are congruent?

6. Congruent
When figures have the same size and shape, they are congruent.
Let’s hear from Mrs. Benson!!
Mrs. Benson!!

7. Bales Bucks!!

8. Symmetry

9. Introduce Please cut out the hexagon and fold it in half.
The fold is a line of symmetry and the two equal halves show line symmetry.
Carefully, punch a pencil through the center of the hexagon.
Rotate the hexagon on the pencil to show rotational symmetry.

10. Teach
Using the letters H, B, I, O, A, and S and a ruler, show a line of symmetry for each letter by drawing the letters on the lined paper.
Can a figure have more than one line of symmetry? Explain.
With one letter, punch a pencil through the center and observe rotational symmetry.
Let’s watch this concept in motion - Symmetry!!

11. Definitions
Line symmetry - a figure has line symmetry if it can be folded so that two parts of the figure match, or are congruent. Also called bilateral symmetry.
Rotational symmetry - when a figure fits exactly over itself after being rotated 180º or less, it has rotational symmetry.

12. Time to be personally tutored!!
Mr. Hardesty!!

13. BALES BUCKS!

14. Assignment Page 433 - #’s 6 - 11 Page 436 - #’s 7 - 16
Get them all correct, No Math Homework