1. In Lesson 4.3.1, you used variables to name lengths that could not be precisely measured.  Using variables allows you to work with lengths that you do not know exactly.  Today you will work with your team to write expressions for the perimeters of different shapes using variables.  As you work with your teammates, use these questions to help focus your team’s discussion:
Which lengths can vary?
How can we see the perimeter?
How can we organize groups of things?

2. 4-85. Using algebra tiles on your desk, make the shapes shown below
4-85. Using algebra tiles on your desk, make the shapes shown below. Trace each shape and label the length of each side on your drawing. With your team, find and record the total perimeter and area for each shape. If possible, write the perimeter in more than one way.
a. b. c.

3. 4-90. Build the following expressions with algebra tiles
4-90. Build the following expressions with algebra tiles. Then rewrite the expression a different way. Remember that parentheses in an algebraic expression allow you to show that tiles are grouped together.
4(2x + 3)
12x + 18
10 + 15x (Hint: Divide into as many equally-sized groups as possible)

4. Practice/Exit Ticket 4.3.2 2x2 + 5x + 8 4. 3x2 – 7x
4x2 – 7x c2 + 4x + 7x – 12 + (-4c2) + 9 – 6x
– 3x2 – 5x – 7
5x + 6
– 4x2 + 6x – 8