There are numbers of shapes and geometrical constructions to be drawn in mathematics for SEE students. Having the knowledge of each and every components inside a geometry box can be really helpful in mathematics class, home and especially in exams. Hopefully we are already familiar with certain geometrical figures such as triangles, square, rectangle, hexagons, circles, perpendiculars and so on. Each shape has unique properties (attributes) or unique combination of properties of its own such as length, breadth, radius, angle. Constructions of triangles and parallelograms and trapezoids can be important questions in SEE exams. In this article you will learn to use instruments inside geometry boxes and be smarter !
Even though with advent in technology sophisticated instruments are there in market, it is always wise to have ideas on how basic instruments on a geometry box work. We are covering few important instruments and see how to use them.
The Ruler
Also known as scale and straightedge in some places, it is mostly used to draw straight line and measure the length of a line segment in centimetres or inches. It is calibrated in millimetres and centimetres on one edge while with inches on the other.
The Compasses
Compass is an instrument used to draw circles and acres. It can also be used to construct angles and triangles. It looks like a ‘V’ shape and holds pencil at one end while with the support of other pointed end it can draw arcs. The distance between pencil and compass point is adjustable and this length also determines the radius of the arc or circle. One should be really careful while handling compass because the pointed end of compass can cause serious injuries.
The Protractor
Mainly used to measure angle a protractor is a semi circular disc. It is graduated from 0 to 180 and 180 to 0 degrees. One can easily draw angles using protractor.
The Divider
A divider that looks much like a compass. However it has two pointers on both ‘V’ ends. With the adjustable distance it is used to measure distance with the help of scale and compare length.
The Set-Squares
These are the triangular pieces of plastic with some portion between them removed. There are two kinds of set squares available in the market. One has the angles 45, 45 and 90 degrees at the 3 vertices while the other has 30, 60 and 90 degree angles. They are used to draw parallel and perpendicular lines
