Perimeter
Area
Finding the Missing Side
Irregular Shapes
Mixed Bag
100
Find the perimeter for this rectangle.
18 units
L + L + W + W = Perimeter
5 + 5 + 4 + 4 = 18 units
100
Find the area of this rectangle.
20 square units
L x W = Area
5 x 4 = 20
100
The area of this rectangle is 54 square units. Find the missing side?
Missing side is 9 units.
L x W = Area
Area ÷ L = W OR Area ÷ W = L
54 ÷ 6 = 9
100
Find the perimeter of this shape.
60 feet
To find the perimeter of a polygon, add up all the sides.
2 + 20 + 10 + 8 + 8 + 12 = 60
* This shape has 6 sides so I should be adding 6 numbers together.
100
A rug had a length of 9 feet and a width of 8 feet. What is the area of the rug?
72 feet long
L x W = Area
9 x 8 = 72 feet
200
Find the perimeter of this equilateral pentagon.
15 inches
To find the perimeter of a polygon (or pentagon) add up all the sides.
3 + 3 + 3 + 3 + 3 = 15 OR 3 x 5 = 15
each side is 3 inches and there are 5 sides
200
Find the area of this square.
49 square units
L x W = Area
7 x 7 = 49
W = 7 & L = 7
200
The perimeter of this rectangle is 22 units. Find the missing side.
The missing side is 7 units.
L + L + W + W = Perimeter
L + L + 4 + 4 = 22
L + L + 8 = 22
22 - 8 = L + L
14 = L + L
14 ÷ 2 = 7
200
Find the perimeter of this polygon.
The perimeter is 15 units.
Add up all the sides to find the perimeter of a polygon.
5 + 4 + 2 + 4 = 15
This polygon has 4 sides so I should be adding 4 numbers.
200
Ryan is building a fence around his yard. He does not need a fence where his house meets the yard. Help him figure out how many yards of fencing he will need.
Ryan needs 34 yards of fencing.
You are finding the perimeter. Add up all the sides, except for the side where Ryan's house meets the yard.
2 + 4 + 6 + 10 + 6 + 4 + 2 = 34
300
A restaurant added a new outdoor section that was 9 feet wide and 5 feet long. What is the perimeter of their new outdoor section?
28 feet
L + L + W + W = Perimeter
5 + 5 + 9 + 9 = 28
300
At the playground, the new sandbox was 4 meters wide and 2 meters long. What is the area of the sandbox?
8 square meters
L x W = Area
4 x 2 = 8 meters
300
A lawn had an area of 90 square feet. If it was 9 feet width, how long was it?
10 feet long
L x W = Area
Area ÷ W = L
90 ÷ 9 = 10
300
What is the perimeter of this equilateral octagon?
The perimeter is 32 inches.
4 x 8 = 32
You multiply by 8 because and octagon has eight sides. Equilateral means all sides are equal in length. Each of the 8 sides in 4 inches long.
300
Find the missing sides of this irregular shape.
Missing Side A: 3 feet
Missing Side B: 2 feet
Step 1: Find Missing Side A
We know that the parallel sides of a rectangle are equal. The vertical sides of both rectangles all equal 3 feet. 3 + 3 = 6, so missing side A equals 3 feet.
Step 2: Find Missing Side B
1 + 9 = 10 Top horizontal line equals 10 feet so the parallel horizontal line should also equal 10 feet.
10 - 8 = 2. Missing side B equals 2 feet.
400
What is the difference between the perimeters of the two shapes below?
The difference is 6 ft.
Step 1: Find the perimeter of each shape
Rectangle: 3 + 3 + 12 + 12 = 30 ft
Triangle: 10 + 6 + 8 = 24 ft
Step 2: Find the difference between the perimeters
30 - 24 = 6 ft
400
What is the area of the shape below?
The area of this shape is 104 square feet.
* First, break the shape into two smaller rectangles. Then, add the area of each rectangle together.
Step 1:
First Rectangle- 8 x 10 = 80
Second Rectangle- 2 x 12 = 24
Step 2:
80 + 24 = 104
400
Find the length of the missing side.
The missing side is 8 ft.
* The parallel sides should be equal in length. The right side of the shape 20 ft. The other side should also add up to 20 feet.
12 + __ = 20 ft
20 - 12 = 8 ft
400
Find the area of this irregular shape.
The total area of the irregular shape is 19 square meters.
Step 1: Break into two rectangles
Green Rectangle: 5 x 3 = 15 square meters
Purple Rectangle: 1 x 4 = 4 square meters
* 7 - 3 = 4
Step 2: Add the two areas together
15 + 4 = 19 square meters
400
Cythina is installing new carpet in her bedroom. Help her figure out how many square feet of carpet she will need to buy.
99 sq. ft.
You are finding the area. Break the shape into two smaller rectangles.
Step 1: Solve for the AREA of each rectangle
Green Rectangle: 8 x 8 = 64 sq. ft
Purple Rectangle: 7 x 5 = 35 sq. ft
Step 2: Add the two areas together
64 + 35 = 99 square feet
500
Mr. Smith wants to build a fence around his garden. The area of Mr. Smith's garden is 60 square meters. The length of his garden is 12 meters. What is the perimeter of Mr. Smith's garden?
Mr. Smith's garden has a perimeter of 34 meters.
First, find the missing side (width) of Mr. Smith's garden. Then, add up all of the sides to find the perimeter.
Step 1: Find the missing side
L x W = Area
Area ÷ L = W
60 ÷ 12 = 5
* Missing side is 5 meters
Step 2: Add the sides together
L + L + W + W = Perimeter
12 + 12 + 5 + 5 = 34
* Perimeter equals 34 meters
500
What is the difference in area between these two shapes?
Shape A
Shape B
The difference is 3 sq. cm.
Shape A Area = 27 sq. cm.
Shape B Area = 24 sq. cm.
500
Find the two missing sides.
A = 2 km
B = 6 km
First Step: Find the length of A
A + 4 = 6
6 - 4 = A
2 = A
Second Step: Find the length of B
B + 1 = 7
7 - 1 = B
6 = B
500
Which irregular shape has a larger perimeter and which irregular shape has a larger area?
Larger Perimeter: Shape B
Larger Area: Shape B
Step 1: Find the Perimeter of Each Irregular Shape
Shape A: 8 + 2 + 3 + 2 + 5 + 4 =24 yards
Shape B: 12 + 10 + 7 + 8 + 5 + 2 = 44 yards
Step 2: Find the Area of Each Irregular Shape
Shape A: (3 x 2) + (5 x 4) = 6 + 20 = 26 sq yrds
Shape B: (5 x 2) + (10 x 7) = 10 + 70 = 80 sq yrds
500
Find the perimeter and the area for the irregular shape below.
Perimeter = 70 ft
Area = 205 square feet
First Step: Perimeter
* Find the two missing sides:
A = 3 + 7 = 10
B = 10 + 15 = 25
Add up all the sides:
10 + 3 + 15 + 7 + B + A =
10 + 3 + 15 + 7 + 25 + 10 = 70 ft
Second Step: Area
* Break the irregular shape into two smaller rectangles.
Blue rectangle:10 x 10 = 100 square feet
Orange Rectangle: 15 x 7 = 105 square feet
Use the distributive Property:
15 x 7 = (10 x 7) + (5 x 7) = 70 + 35 = 105
Add Blue and Orange areas together:
100 + 105 = 205 square feet
