RD Sharma Class 10 Solutions Chapter 11 - Exercise 11.2

Geometrical Constructions are the Geometrical figures that we construct using Geometrical instruments. Each of these instruments or tools have a different working of their own. 

Some of the most used geometric tools are as follows:

• Ruler 

• Compass

• Protractor

• Divider

• Set squares

Ruler 

Rulers are used to measure the length of a line segment and to construct it as well. It is used in geometry as well as engineering applications. It is initially used for drawing straight lines. Generally, for our convenience, rulers have centimeters and millimeters on one side and inches on the other side. The intervals of the markings mentioned on the ruler are called hash marks. 

Compass

A Compass is a ‘V’-shaped tool that can hold a pencil on one side  and a pointed end on the other side. The distance between the two is adjustable. Compass is used to trace arcs, circles, angles, etc. it can also be used to mark equal lengths. Compass is one of the most used Mathematical tools which is used to draw a geometrical figure, such as a circle. It is also used to make the intersection of line segments and tools, which is used to intersect the line segment and helps us to find the midpoint of the shapes.

Protractor 

A Protractor is a semi-circular instrument used to construct and measure different angles. It starts from 0 degrees and goes up to 180 degrees and can be used directly to measure any angle within this range. It has two sets of markings. 0 to  180 degrees from left to right of the instrument and vice versa. While measuring an angle using a protractor, we need to follow the steps that are given below:

• If the angle is to be measured at the left side of the protractor, we have to use the outer reading provided in the protractor.

• If the angle is to be measured at the right side of the protractor, we have to use the inner reading provided in the protractor.

Divider

A divider looks similar to a protractor. The only difference is that it has pointed ends on both sides. The distance between these sides is adjustable. A Divider is used to measure and compare the lengths. Dividers have two ends in which one sharp endpoint is used as a center, and the other sharp endpoint is used for marking.

Set Squares

Set squares are also one of the Mathematical tools, which are found commonly in geometry boxes. These are triangular in shape. There are two kinds of set squares where one  has an angle of 45 degrees and the other has 30-60 degrees. The 45 degree set square has an angle of 90 degrees, and also 30/60 degree set square has a right angle. The 45 degrees set square is used to draw vertical lines. These are also used to draw parallel lines, perpendicular lines, make some standard angles, and so on.