and Other Measuring Tools
These are examples of  acrylic (plastic) rulers. Clear acrylic rulers work very well with pencils or markers.
Acrylic rulers can also have interesting shapes within the ruler. These can be very useful in designing.

To the side are 30, 40 and 50cm steel rulers. 
T Square
Circle Protractor
15cm 30 cm 50cm rulers
This student is measuring a piece of cardboard. She will use a steel ruler as a guide and a utility knife  to cut it.
Below is a utility knife. It is sharp and dangerous. Use it with
adult supervision.