Starter
1cm
2cm
2cm
1cm
1cm
2cm
The area of a rectangle is ……………………………
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We are learning to:
• Understand how to work out the area of a triangle
• Know and understand the formula for the area.
Key idea:
We can think of every triangle having it’s own rectangle
Key words:
base, height, area.
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area2011
of these rectangles is …
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Off cuts
Cut out
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What do you notice?
Might it always be true?
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4.
What are the areas of the four triangles
5.
How do you work out the area of a triangle e.g this one below.
4.
6. So the formula (or method is) ?
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c
b
a
d
For each rectangle work out it’s area.
a = _____
b = _____
c = ______
d = ______
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How many of the triangles fit into each rectangle?
________
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Extension 1
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Extension 2
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