Compound Areas
In this activity we are going to look at areas of compound shapes, and how many measurements we need to calculate the areas.
Look at the shape below.
Which lengths do you need to know to be able to calculate the perimeter of the shape?
What is the minimum number of lengths you need?
Which lengths do you need to know to be able to calculate the area of the shape?
What is the minimum number of lengths you need?
Use the checkboxes to reveal as few lengths as possible to calculate these two measurements.
Type the value you get for the area of the shape into the answer box, and press the "Check" button to check your answer.
Move on to the next question and do the same.
Look at the shape below.
Which lengths do you need to know to be able to calculate the perimeter of the shape?
What is the minimum number of lengths you need?
Which lengths do you need to know to be able to calculate the area of the shape?
What is the minimum number of lengths you need?
Use the checkboxes to reveal as few lengths as possible to calculate these two measurements.
Type the value you get for the area of the shape into the answer box, and press the "Check" button to check your answer.
Move on to the next question and do the same.
Ideas for Teachers
This activity is a self contained set of questions, and would make an ideal homework, with screenshots to show their work.
From the board, you could show the problem and get them to sketch it. Then ask them how many of the lengths do they need to calculate the perimeter. Show some lengths using the checkboxes (the ones they ask for), and get them to calculate the perimeter. Now uncheck the boxes, and ask what is the minimum number of lengths needed to calculate the area. This will provide various results, depending on their method of finding the area.
Although simply finding the area and perimeter is a good use of this activity, the extra dimension provided by using the minimum inforation should get even the most able really thinking.
Even better? There are three ready questions (more to come) and every one is editable so you can create your own.
This activity is a self contained set of questions, and would make an ideal homework, with screenshots to show their work.
From the board, you could show the problem and get them to sketch it. Then ask them how many of the lengths do they need to calculate the perimeter. Show some lengths using the checkboxes (the ones they ask for), and get them to calculate the perimeter. Now uncheck the boxes, and ask what is the minimum number of lengths needed to calculate the area. This will provide various results, depending on their method of finding the area.
Although simply finding the area and perimeter is a good use of this activity, the extra dimension provided by using the minimum inforation should get even the most able really thinking.
Even better? There are three ready questions (more to come) and every one is editable so you can create your own.
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