Transcript Slide 1

Opening Activity
Shapes
In your spiral, create a word map of what you
think of when you hear the word “shapes.”
Perimeter of Polygons
Area of Rectangles and
Parallelograms
Learning Goal 610
Students will be able to solve real-world and mathematical
problems involving area.
 I can draw polygons on the coordinate plane when given the
vertices.
 I can find the length of a side of a polygon graphed on the
coordinate plane.
 I can determine the area of squares and rectangles.
 I can calculate the area of triangles
 I can calculate the area of special polygons by breaking the
polygon into familiar shapes.
 I can take everything I’ve learned about area and apply it to
real-world situations.
What are we doing today?
 Today I am working with perimeter and area.
 So that I can determine the perimeter of any
given polygon and determine the area of
rectangles and parallelograms.
 I’ll know I’ve got it if I can determine the
perimeter and area of the shape below.
8
2
3
Perimeter
 Perimeter is the distance
around a two-dimensional
shape.
 When you think of
perimeter think of walking
the fence around the
perimeter of a yard.
 You walk the length of each
side and add the lengths up
to get the total distance
walked.
5
18cm
6
4
3
18cm
11
26cm
2
3
3
3
18cm
Find the perimeter.
Can we work backwards?
7
22 cm
What is the missing side length of the rectangle
above?
4 cm
BRAIN BREAK
Area
 Area is the number of
square units contained
within a shape.
 While the perimeter is the
fence around the yard, the
area is the space contained
in the yard.
https://www.youtube.com/watch?v=qU8aWpRd6Qw
The rectangle is made of 6 rows of 8 squares.
To work out the number of squares
we times 6 by 8.
The area of the shape is 48cm2.
20cm2
18cm2
14cm
2
22cm
2
We can work out the area of a rectangle
without the grid.
length
width
Area = length x width
CHECK YOUR PROGRESS
7cm
9cm
2
36cm
35cm2
5cm
20cm2
5cm
12.5cm
4cm
2cm
25cm2
4cm
Area of parallelogram
height
base
 Area of parallelogram = base x height
Which dimensions do we use?
4 cm
5 cm
6 cm
What is the area of this parallelogram?
A = bh
A = (6)(5)
A = 30 cm2
CHECK YOUR PROGRESS
3 ft
5 in
8 ft
4 in
9 ft
6 in
A = bh
A = (3)(8)
A = 24 ft2
A = bh
A = (6)(5)
A = 30 in2
LET’S WORK BACKWARD
9 ft
h
2
45
ft
2
9 ft
A = bh
45 = 9h
9
9
h = 5 ft
8 ft
6 ft
Homework
 Perimeter and Area Worksheet
 Due at the start of next class