Real World Use
What does perimeter measure?
The length of the sides of a shape or figure.
What are three examples of units we have learned about this unit?
feet, centimeters, inches, meters, etc.
A rectangular piece of cheese is 9 centimeters long and 5 centimeters wide. What is the perimeter of the cheese? Show your work and be ready to share your strategy!
9 cm + 9 cm + 5 cm + 5 cm = 28 centimeters or 28 cm
Sarah is painting a picture where each side measures 7 inches. How much paint will she need to cover the square picture? Show your work and be ready to share your strategy!
7 in x 7 in= 49 square inches or 49 in2
What is the area of a shape if it has the height of 6 cm and a width of 6 cm? Show your work and be ready to share your strategy!
6 cm x 6 cm = 36 square centimeters or 36 cm2
What does area measure?
The space inside a shape or figure.
What is perimeter measured in?
units
What is the perimeter of a tv that has dimensions of 24 ft and 18 ft? Show your work and be ready to share your strategy!
24 ft + 24 ft + 18 ft + 18 ft = 84 feet or 84 ft
Lucy is counting the ceiling tiles in her gym. The dimensions of the ceiling are 46 ft by 9 ft. What is the area of the ceiling? Show your work and be ready to share your strategy!
46 ft x 9 ft = 414 ft 2 or 414 square feet
What is the perimeter of a square with sides measuring 9 meters? Show your work and be ready to share your strategy!
9 in + 9 in + 9 in + 9 in = 36 square meters or 36 m2
Molly wants to buy carpet for her tree house, what will she use to find how much carpet she needs to buy?
Area
We can multiply the dimensions together to find area. What are dimensions?
length and width
A rectangular table is 98 centimeters long 45 centimeters wide. What is the perimeter of the table? Show your work and be ready to share your strategy!
98 cm + 98 cm + 45 cm + 45 cm = 286 centimeters or 286 cm
Karen's grandma is making her a quilt. The dimensions of the quilt are 6 ft by 12 ft. What is the area of the quilt? Show your work and be ready to share your strategy!
12 ft x 6 ft = 72 square feet of 72 ft2
Mrs. Whitehill needs to get a new washer. The washer must fit in a space with an area of 100 in2. The dimensions of the washer are 10 in. by 15 in. Will the washer fit? Show your work and be ready to share your reasoning!
The washer will not fit. The washer has an area of 150 in2 which is bigger than 100 in2.
10 in x 15 in = 150 in2
To build a fence, I would measure...
Perimeter
What is area measured in? Why?
Square units because because shapes and figures are made up of squares. Area area tells us how many squares make up a shape or figure.
Sarah is putting fence around her garden. She knows the perimeter is 48 feet. She has already fenced in three sides and they each measure 12 feet. How much more fence does she need to finish making her fence? Show your work and be ready to share your strategy!
12 ft + 12 ft + 12 ft = 36 ft
48 ft - 36 ft = 12 feet or 12 ft
Sarah has a square garden. One side is 8 ft long. What is the area of the garden? Show your work and be ready to share your reasoning!
The sides of a square are equal so I can add 8 ft + 8 ft + 8 ft + 8 ft to get 32 ft2 or I can multiply 8 ft x 4 ft to get the same answer.
Ms. Whitehill wants to build a tree house. She wants it to be 10 feet in width and 9 feet in height. What will be the area of her tree house be? Show your work and be ready to share your strategy!
10 ft x 9 ft = 90 square feet or 90 ft2
You are building a sandbox. You need to build a fence and figure out how much sand to put inside of the fence. Will you have to measure for area or perimeter?
Area for the sand.
Perimeter for the fence.
The dimensions of Justin's carpet are 4ft by 6ft. What units will be used for the area?
square feet or ft2
Terry is putting trim around a triangular picture frame. He knows he needs 27 centimeters of trim. Two of the sides are both 8 centimeters long. How long is the third side? Show your work and be ready to share your strategy!
8 cm + 8 cm = 16 cm
27 cm - 16 cm = 11 centimeters or 11 cm
Josh was measuring his Math in Focus book. It is 8 inches wide by 11 inches long. What is the area of the book? Show your work and be ready to share your strategy!
8 in x 7 in = 56 square inches or 56 in2
Mrs. Snowden wants to add on a new addition to the school. If the school already measures 2000 ft2, what will be the new area of the school if the new addition measures 12 feet in width and 12 feet in length? Show your work and be ready to share your strategy!
12 ft x 12 ft = 144 ft2
2000 ft2 + 144 ft2 = 2144 ft2