Transformation Post 4

Rotation. 

Rotation is an important transformation for you to have solid understandings with.  A rotation is just when we spin the object (remember objects have labels like ABCD or PQRS). 

When we rotate we have to know three main things...

1. Which direction - there are two clockwise or anti-clockwise.
2. How many degrees - remember that a right turn is 90 degrees.
3. Where is the 'centre of rotation' - this is the anchoring point that the image is "swung around".

 You will need a protractor to carefully measure the size of the angles you are rotating. 

A trick is to think of Spiderman and his web.  Think of Spiderman sitting at the 'centre of rotation' - he fires his webs out onto an object and then rotates/spins them around him. 

Another trick is to use some clear overhead transparency paper and a compass point to pin down the centre of rotation. 

The final trick is that if the instructions just say rotate ABC 90 degrees around point A.  see there is no direction given.  Then we just make the decision to go anticlockwise.