Perimeter Make 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 the rim eterPeof 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.

is the distance around the rim eterPeof a figure. rim 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.

is the distance around therimeterPeof a figure.rim 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 ft5 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.

is the distance around therimeterPeof a figure.rim 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   = …(goes on forever! It is irrational.) Pi represents the number of times the diameter of a circle fits around the circumference of the circle.

is the distance around therimeterPeof a figure.rim Remember the perimeter of a circle is called the circumference. To find the circumference of a circle, use C = 2  r 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 = 2  r C = 2 x 3.14 x 6 ft C = ft The distance around my pool is 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 therimeterPeof 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 = 2  r 1.) Find the perimeter of the rectangle. 7 ft 5 ft Try solving the problem before moving to the next slide.

is the distance around therimeterPeof a figure.rim Make sure your answer includes the units (feet, inches, centimeters, etc.)! *To find the circumference of a circle, use C = 2  r 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): Make sure your answer includes the units (feet, inches, centimeters, etc.)! 3 cm is the distance around therimeterPeof a figure.rim *To find the circumference of a circle, use C = 2  r Try solving the problem before moving to the next slide. *To find the perimeter of a figure, you add all the sides.

Make sure your answer includes the units (feet, inches, centimeters, etc.)! is the distance around therimeterPeof a figure.rim *To find the circumference of a circle, use C = 2  r 2.) Find the perimeter of the triangle (all sides are equal): 3 cm To find the perimeter, add all the sides. There are three sides of 3 cm. 3 cm + 3 cm + 3 cm = Did you get 9 centimeters? Your math should look something like this… *To find the perimeter of a figure, you add all the sides.

3.) Find the circumference of the circle: Make sure your answer includes the units (feet, inches, centimeters, etc.)! 5 cm is the distance around therimeterPeof a figure.rim *To find the circumference of a circle, use C = 2  r Try solving the problem before moving to the next slide. *To find the perimeter of a figure, you add all the sides.

Make sure your answer includes the units (feet, inches, centimeters, etc.)! is the distance around therimeterPeof a figure.rim *To find the circumference of a circle, use C = 2  r 3.) Find the circumference of the circle: 5 cm To find the circumference use: C = 2  r 2 x 3.14 x 5 cm = Did you get 31.4 centimeters? Your math should look something like this… *To find the perimeter of a figure, you add all the sides.

Make sure your answer includes the units (feet, inches, centimeters, etc.)! is the distance around therimeterPeof a figure.rim *To find the circumference of a circle, use C = 2  r 4.) Find the perimeter of a rectangle with a length of 6 yards and a width of 8 yards. Try solving the problem before moving to the next slide. *To find the perimeter of a figure, you add all the sides.

I find drawing a picture with labels makes problems like this easier. To find the perimeter, add all the sides. 6 yd + 6 yd + 8 yd + 8 yd = Did you get 28 yards? Make sure your answer includes the units (feet, inches, centimeters, etc.)! 6 yd 8 yd is the distance around therimeterPeof a figure.rim *To find the circumference of a circle, use C = 2  r 4.) Find the perimeter of a rectangle with a length of 6 yards and a width of 8 yards. Your math should look something like this… *To find the perimeter of a figure, you add all the sides.

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