When using translation you always need to say:
How many times bigger you have made the shape (scale factor)
What the centre of enlargement is
The centre of enlargement is the point of which the shape started to enlarge (form)
The scale factor is how many times the shape is being enlarged.
The easy way to work out the scale factor of a shape on a grid is to first count how many squares are on one side of the smaller shape (preferably the bottom) you then count how many squares there are ON THE SAME SIDE on the enlarged shape. You then compare the two numbers and work out how many times the shape has been enlarged. (I like to use division)
Here, the first shape (pink) has 4 squares along the bottom side. In the enlarged shape the bottom side has 8 squares. I then use division to work out the scale factor.
8 divided by 4 gives 2. So 2 = the scale factor.
When working out the scale factor of a shape with no grid you use projection lines. Here is an example of what projection lines look like:
First you draw a projection line, starting from the middle of the X to one of the corners of the shape and beyond. You then measure that distance and double it. Then, starting from the X along the projection line you apply that doubled distance and then place a small mark at the end of the doubled distance. Repeat this for all of the corners. Your shape should now look like this:
What the centre of enlargement is
The centre of enlargement is the point of which the shape started to enlarge (form)
The scale factor is how many times the shape is being enlarged.
The easy way to work out the scale factor of a shape on a grid is to first count how many squares are on one side of the smaller shape (preferably the bottom) you then count how many squares there are ON THE SAME SIDE on the enlarged shape. You then compare the two numbers and work out how many times the shape has been enlarged. (I like to use division)
Here, the first shape (pink) has 4 squares along the bottom side. In the enlarged shape the bottom side has 8 squares. I then use division to work out the scale factor.
8 divided by 4 gives 2. So 2 = the scale factor.
When working out the scale factor of a shape with no grid you use projection lines. Here is an example of what projection lines look like:
First you draw a projection line, starting from the middle of the X to one of the corners of the shape and beyond. You then measure that distance and double it. Then, starting from the X along the projection line you apply that doubled distance and then place a small mark at the end of the doubled distance. Repeat this for all of the corners. Your shape should now look like this:
Once you've done that you join up all of your new doubled distances to create a new and enlarged shape like so,
That is how you enlarge a shape without a grid. The tricky thing is though, even though you've enlarged the shapes all the angles are actually still the same!
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