perimeter make sure you have your mini-lesson paper in front of you. you will know you need to write...

PerimeterMake sure you have your mini-lesson paper

in front of you.

You will know you need to write something on the notes because it will be underlined.

The Mini-Lessons are meant to be mini! Only do the assigned part each day.

Today you will only work on the notes and Part A.

Click the forward button to view the next slide.

This button will take you back a slide.

The writing above is underlined. This means there is something for you to write on your paper.

is the distance around therimeterPe of a figure.rim

Read the definition out loud.

I can’t hear you!

Do you notice anything similar about the word perimeter and the definition?

Look above!

Now watch me walk around the perimeter of my garden.


With your finger, trace around the perimeter of the triangle and the hexagon.

The perimeter of a circle is called the circumference. Trace your finger around the circumference of the

circle.


Let’s say my garden has a length of 5 feet and a width of 3 feet.

As I walk along the perimeter of my garden I walk a length of 5 feet,

then a width of 3 feet, then another length of 5 feet, and then another

width of 3 feet.

To find the perimeter of a figure, you add all the sides.

Circles are an exception.

5 ft

3 ft

To find the perimeter of my garden I just have to add all the

sides.5 ft + +3 ft 5 ft + 3 ft = 16 ft

6 cm 4 cm

5 cm

6cm + 4 cm + 5 cm = 15 cm

The perimeter of the triangle is 15 cm.


Now we are going to find the perimeter of my circular pool. The perimeter of a circle is called the

circumference.

Before I tell you how to find circumference, let me go over a little vocabulary.

r

The distance from the center of a circle to the outside is called the radius.

Last thing is Pi. Pi is represented with the symbol = 3.14159…(goes on forever! It is irrational.)

Pi represents the number of times the diameter of a circle fits around the circumference of the circle.


Remember the perimeter of a circle is called the circumference.

To find the circumference of a circle, use C = 2r

That is “circumference equals two times Pi times radius.”

6 ft

If the radius of my pool is 6 feet, then I can find the circumference of the pool by “plugging into” the formula.

(You can use 3.14 for Pi)C = 2r

C = 2 x 3.14 x 6 ftC = 37.68 ft

The distance around my pool is 37.68 feet.

OK it is time to work on Part A.

Remember to attempt to solve the problem first before you watch the solution on the following

slide.

Show all of your work!No calculators.

is the distance around therimeterPe of a figure.rim*To find the perimeter of a figure, you add all the sides.

Make sure your answer includes the units (feet, inches, centimeters, etc.)!

*To find the circumference of a circle, use C = 2r

1.) Find the perimeter of the rectangle.

7 ft

5 ft

Try solving the problem before moving to the

next slide.




1.) Find the perimeter of the rectangle.

7 ft

5 ft

Your math should look something

like this…

To find the perimeter, add all the sides.

There are two lengths of 7 ft and two widths of 5 ft.

7 ft + 7 ft + 5 ft + 5 ft =

Did you get 24 feet?

*To find the perimeter of a figure, you add all the sides.

2.) Find the perimeter of the triangle (all sides are equal):


3 cm




next slide.





2.) Find the perimeter of the triangle (all sides are equal):

3 cm


There are three sides of 3 cm.

3 cm + 3 cm + 3 cm =

Did you get 9 centimeters?


like this…


3.) Find the circumference of the circle:


5 cm




next slide.





3.) Find the circumference of the circle:

5 cm

To find the circumference use:C = 2r

2 x 3.14 x 5 cm =

Did you get 31.4 centimeters?


like this…





4.) Find the perimeter of a rectangle with a length of 6 yards and a width of 8 yards.


next slide.


I find drawing a picture with labels makes problems like this easier.


6 yd + 6 yd + 8 yd + 8 yd =

Did you get 28 yards?


6 yd

8 yd



4.) Find the perimeter of a rectangle with a length of 6 yards and a width of 8 yards.


like this…


You are done! Click on the return button on

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class webpage.

perimeter make sure you have your mini-lesson paper in front of you. you will know you need to write...

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