When we need to draw some angle then we use the geometrical tool known as a protractor. The protractor scale is graduated in degrees. Thus, it can also be used to measure any unknown angle. Generally, a protractor consists the graduation scale from 0 degrees to 180 degrees. But it can also consist of a whole 360 degree of graduations, that is, a full circle.
A divider almost looks, like a compass. It is also v in shape. But unlike in a compass, it does not consist of a pencil holder in one of its arms. In a divider, both of its arms are pointed at one of their ends. When we need to compare two lengths of any measurement then we use the divider. It can also be used to measure the unknown length with the help of a ruler.
Now, if we need to draw a parallel line or even a perpendicular line then we can use a set square. To talk about the structure of a set square, it has a body which is usually made up of plastic. It is triangular and consists of graduations which can vary. there are usually two types of set squares. One is where the three angles of the triangle are 90 degrees and 45 and 45 degrees, whereas the other has angles as 90, 60 and 30 degrees.