# CBSE Class 6 Maths Revision Notes Chapter 14

## CBSE Class 6 Mathematics Chapter 14 Revision Notes – Practical Geometry

Practical Geometry is an important chapter for learning the fundamentals of geometry. The CBSE Syllabus introduces students to the basic rules of geometry in Class 6. In Chapter 14 of Class 6 Mathematics, students learn to use basic geometric tools like rulers and compass, to construct a copy of a line segment and an angle of unknown measure. Class 6 Mathematics Chapter 14 Notes provided by Extramarks have simplified all the topics so that students can grasp them easily.

The notes are prepared by subject matter experts as per the latest CBSE Syllabus and guidelines. Every topic is explained step-by-step so students can refer to the notes while solving  the questions. The Class 6 Mathematics Chapter 14 Notes are comprehensive and will boost students’ confidence in their exam preparations. They will be able to solve  Important Questions by carefully going through  these notes.

Class 6 Mathematics Chapter 14 Notes are easily accessible on the website. So, students can access them and prepare for their exams effectively.

### Revision Notes For CBSE Class 6 Mathematics Chapter 14Access Class 6 Mathematics Chapter 14 – Practical Geometry – Notes

Constructing a Copy of a Given Line Segment

A copy of a line segment can be easily constructed using a ruler and a compass. Follow the steps to draw an exact copy of the given line segment.

Suppose, AB is a given line segment.

Step 1: Place the compass pointer on point A and place the tip of the pencil on point B. The distance between the pointer and the pencil tip  is equal to the length of AB.

Step 2: Draw another line with the pencil and choose a point, say C. Now, place the compass pointer on point C  without changing the position of the compass.

Step 3: Draw an arc on a straight line while maintaining the position of the compass. For example, the arc cuts the straight line at point D.

Now, the line CD is a copy of the line segment AB.

### Method of Ruler And Compass

In this segment, the methods of using a ruler and making arcs with a compass will be discussed.

Step 1: Draw a line segment l. Choose a point on l. Consider the point as P.

Step 2: Place the compass pointer on P and draw an arc on the line segment. Suppose, the arc cuts the line segment l at points A and B.

Step 3: Now, place the compass pointer on point A and draw an arc whose radius will be greater than the length of AP.

Step 4: Follow the same method while making B the centre of the other arc.

Step 5: Both arcs cut each other at a point. Give the point a name, say Q.

Step 6: Join P and Q.

Now, PQ is perpendicular to AB. Since, PQ ⊥ AB, hence, PQ ⊥ l.

### Constructing a Copy of an Angle of Unknown Measure

A straightedge/ruler and a compass is enough to construct a copy of an angle of unknown measure.

Suppose, ∠A is the given angle. Follow the steps mentioned below to make a copy of ∠A.

Step 1: Draw a line segment and choose a point where the angle is to be constructed. Consider the chosen point as P.

Step 2: Put the compass pointer on point A and draw an arc. Suppose, the arc cuts the rays of the angle at points B and C.

Step 3: Maintain the same position of the compass and place it on point P to make an arc on the line segment. Name the point where the arc cuts the line segment. Suppose the point is Q.

Step 4: Measure the distance between B and C. Draw an arc on the line segment, making Q the centre and the distance between B and C the radius.

Step 5: This arc cuts the other arc drawn earlier on point P at point R.

Step 6: Join P and R. An angle is thus formed whose measurement is the same as that of ∠A.

Therefore, ∠QPR = ∠BAC.

### 1. Describe the method of constructing a copy of a line segment.

A line segment is a part of a line with two distinct endpoints. A ruler and a compass will be required to make a copy of it. Draw a line segment with a sharp pencil. Measure the length of the given line segment by placing the compass pointer at one end and the pencil of the compass at the other end. Now, draw an arc on the newly drawn line segment by placing the compass pointer on one end. The distance between the arc and the end point of the line segment is equal to the length of the given line segment.

### 2. How can a copy of an angle of unknown measure be constructed using a ruler and a compass?

To construct a copy of an angle of unknown measure, the steps given below must be followed:

1. Draw a line and choose a point on it, say X.
2. Place the compass pointer on the given angle, say ∠S, and draw an arc which cuts the rays of ∠S at R and T points.
3. Maintaining the position of the compass, make an arc on point X. This arc cuts the line segment at point Y.
4. Measure the distance between R and T.
5. Place the compass pointer on Y.
6. Make another arc that cuts the arc drawn earlier at point Z.
7. Now, join X and Z.
∠ZXY = ∠RST.

### 3. Except for the line segment and copy of an angle, what other constructions can be created using a ruler and a compass?

The following constructions can be created using a ruler and a compass.

• A circle can be drawn when the length of the radius is given.
• A line segment can be drawn using the ruler and compass.
• A perpendicular can be drawn on the line segment.
• A perpendicular bisector can be drawn if the length of the line segment is given.
• An angle of a given measure can be drawn.
• A copy of an angle can be drawn.
• The bisector of a given angle can also be drawn.
• Some angles that have special measurements can be constructed, such as:
• 30⁰
• 45⁰
• 60⁰
• 90⁰
• 120⁰
• 135⁰

### 4. How can Class 6 Mathematics Chapter 14 Notes help students?

Class 6 Mathematics Chapter 14 Notes discuss all of the concepts given in the textbook in a comprehensive and easily understandable language.  Subject matter experts have consulted the revised CBSE Syllabus before preparing the notes. So, students need not worry about outdated content. They can prepare for all types of questions, especially those that are important from an exam point of view. . These notes will help students get conceptual clarity and resolve  all their doubts to step up their preparation for the exams without any further assistance.