Lesson 18 — Activity 1: Measuring the Area of a Rectangle
Completion requirements
Lesson 18 — Activity 1:
Measuring the Area of a Rectangle
Image Source: Pixabay
I need to calculate how much fabric to buy to make
tablecloths to cover the tables for an event.
How can I do this?
Is there a simple way to figure this out? Yes, there is — you need to find the
area
of the surface of the
table.
How can I do this?
Is there a simple way to figure this out? Yes, there is — you need to find the area of the surface of the table.
Area is calculated in various ways depending upon the type of surface.
Area refers to the number of square units that cover a surface. Area is most commonly determined by multiplying the length (l) by the width (w).
Area of a square or rectangle = the length (l) of one side multiplied by the width (w) of the other side.
The formula is written this way:
A = l × w (length x width)
Sometimes the
multiplication
sign is omitted as follows:
A = lw
OR
A = w x h (width x
height
)
Area is always measured in "square" units. Notice the little "2" that is higher than the "m" in the example below? That means that the rectangle is 6 metres squared.
Let's try another example!
Jackson likes to skate at the local outdoor rink in winter. The rink measures 5 metres long by 2 metres wide. What is the area of the rink?
Another way to think about area when you think about square units is to count the number of squares inside a rectangle.
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Remember: Area is always measured in square units. So, the area of the rectangle above is 40 feet squared (8 feet x 5 feet = 40 feet squared.)
Click on the Play button below to watch a video on how to find the area of a square and a rectangle.
Self-check!
Try This!
Try answering the questions below on your own first. When you have finished, click on the tabs below to check your answers!
Find the area of an envelope that measures 6 inches on one side and 3 inches on the other.
Find the area of a sheet of paper that measures 11 inches by 14 inches.
Calculate the area of a tile that has a width of 30 mm by a
length
of 50 mm and is used for making a
table top.
Area of the envelope: 6 x 3 = 18 in squared
Area of a sheet of paper: 11 x 14 = 154 in squared
Area of a tile = 30 x 50 = 1,500 mm squared