BellringerWEDNESDAY SEPTEMBER 26, 2012

Simplify the expression below.

2x + x + 2 + 10 + 3x = 30

6x + 2 + 10 = 30

6x + 12 = 30 -12 -12

6x = 18

6 6x = 3

A. x = 2B. x = -3C. x = 3D. x = 5E. x = 4

Benchmark 3I can find the perimeter of

basic geometric objects using Algebraic Expressions.

2x

2x

Brief Review

What is perimeter?

Perimeter is the total distance around the

outside of a 2D shape.

You calculate it by adding together all the

lengths of a shape.

Example 1: WE DO

Find the perimeter of the figure below.8 cm

4 cm

8 + 8 + 4 + 4 = 24 cm

example 2: WE DO

Find the perimeter of the figure below.

??

3

22

2

8+ 3 + 6 + 2 + 2 + 2 + 3 =

26 ft2

example 3: YOU DO

Find the perimeter of the figure below.

2

332

2

7

2

3

7 + 2 + 2 + 3 + 2 + 3 + 3 + 2 =

24 ft

2

Sage-n-Scribe Activity

Using ONE pencil, you and your shoulder partner will complete the problems on your worksheet..

The sage will tell the scribe how to do problem 1 and the scribe will write down what his/her partner says, making corrections as necessary. Then switch roles.

Bellringerthursday september 27, 2012

example 4: WE DOThe perimeter of this rectangle is 24

ft. What is the value of x?

2x

x

2x

x

2x + 2x + x + x = 24 6x = 24

6 6

x = 4

example 5: YOU DOThe perimeter of this triangle is 18

cm. What is the value of x?

x + 2

6

x + 2

(x + 2) + (x + 2) + 6 = 18

2x + 2 + 2 + 6 = 18

2x + 10 = 18

-10 -10

2x = 8

2 2

x = 4

Example 6: WE DOA rectangle has a perimeter of 48 feet.

its width is double thE LENGTH. find the dimensions (length & width). DRAW A PICTURE TO GET YOURSELF

STARTED!

WIDTH

LENGTH

W = 2L W = 2L

L

L

2L + 2L + L + L = 486L = 48

6 6

LENGTH = 8WIDTH = 16

WIDTH = 2(L)WIDTH = 2(8)

Example 7: YOU DOA rectangle has a perimeter of 3o feet.

THE LENGTH IS 3 FEET LONGER THAN THE WIDTH. find the dimensions (length & width).

W W

L = W + 3

L = W + 3

(w + 3) + (w + 3) + w + w= 304w + 6 = 30

-6 -6

4w = 24

4 4w = 6

width = 6length = 9

LENGTH= W + 3

LENGTH= 6 + 3

Sage-n-Scribe Activity

Using ONE pencil, you and your shoulder partner will complete the problems on your worksheet..

The sage will tell the scribe how to do problem 1 and the scribe will write down what his/her partner says, making corrections as necessary. Then switch roles.

HOMEWORK

NONE!

Exit SlipTake a notecard out of your table bin and write your name, class period, and exit slip solution on the card.

As you leave, please put it in the tray with your class period label.

Exit Slip (Side 1)The perimeter of this rectangle is 16

ft. What is the value of x?

3x

x

Exit Slip (Side 2)Exit Slip (Side 2)Clarity of Lesson

Flip your notecard over to the other side.

Using a # from 1-5, write down the clarity of this lesson.

1 = “I don’t understand at all! HELP!”5 = “This is a piece of cake!!”

I am still confused about...I don’t get...

VIDEO??