Your answers to 1B should look something like this:-
| (a) | (b) | |
| 1. | The page is a rectangle so to work out the area I need the length and the width. I multiplied these measurements together to get the area |
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| 2. | For the area of a triangle I need the base and the height. I multiply these measurements together and multiply by a half to get the area. |
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| 3. | To work out the area of a circle I need its radius. I multiply the radius by itself and then multiply by the number pi, which is 3·1415926 |
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| 4. | For the perimeter of a rectangle I need the length and the width.I add these two measurements together and then multiply this by two. |
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Not only is the mathematical method less writing, it is also much more precise than the words. And with a little practice is easier to use.
As soon as you use symbols, such as
A for area, l for length or r for radius, and so on, then you are doing algebra.The formula not only tells you what measurements are needed, but also what to do with those numbers when you have got them.
You may have noticed in the calculations above that multiplication is used rather more than any other arithmetic process and so some writing is saved by not writing the multiplication symbol, but adopting algebra’s first rule that where there is no sign between two variables, then multiply.
