Practical Geometry
Overview
Practical Geometry is about drawing accurate geometric figures using basic tools like a ruler, compass, protractor, and set squares. In this chapter, Class 6 students learn to construct a circle, a line segment, perpendicular lines, parallel lines, and angles of given measures. These constructions help us create precise shapes that are used in real life, architecture, and design. Following the correct steps makes every drawing exact and reliable.
Typed Notes
Drawing a Circle and a Line Segment
To draw a circle, set the compass to the required radius by placing it against a ruler. Fix the pointed end at the centre point and rotate the compass fully to get a perfect circle. To draw a line segment of a given length, place the ruler on paper, mark two points at the required distance apart, and join them with a sharp pencil. Always keep the pencil tip close to the ruler edge so the line is straight and accurate.
Constructing Perpendicular Lines
A perpendicular bisector of a line segment AB is drawn using a compass. Open the compass to more than half the length of AB. Place the compass at A and draw arcs above and below the segment. Without changing the compass width, repeat from point B. The two arcs meet at points P and Q. Join P and Q with a ruler. The line PQ is the perpendicular bisector of AB, cutting it at its midpoint at exactly 90°. This method is very accurate compared to using a protractor.
Constructing Parallel Lines and Angles
To draw a line parallel to a given line through a point, use a ruler and set square or the equal-alternate-angles method with a compass. To construct an angle of a given measure, place the protractor's centre on the vertex, align the baseline with one arm, mark the required degree, and join the vertex to that mark. To bisect an angle, draw arcs from the vertex cutting both arms, then draw intersecting arcs from those points and join the vertex to the intersection point.
Key Concepts
Revision ke liye ek nazar — exam se pehle yahi padhna hai.
- 01A compass is used to draw circles and arcs of a given radius.
- 02A perpendicular bisector divides a line segment into two equal halves at 90°.
- 03An angle bisector divides a given angle into two equal smaller angles.
- 04Parallel lines are always the same distance apart and never meet.
- 05A protractor is used to measure and draw angles accurately.
Questions & Solutions
Pehle khud try karo — phir solution kholo. Yahi tariqa topper banata hai.
Draw a line segment PQ of length 6 cm and construct its perpendicular bisector.
Construct an angle of 60° at point O on a line.
Draw a circle of radius 4 cm.
Bisect an angle of 80° using a compass.
Draw a line segment AB = 8 cm. Find its midpoint using a compass.
In Practical Geometry, we use a ruler, compass, protractor, and set squares to draw exact figures. Key constructions include circles of given radius, line segments of given length, perpendicular bisectors, angle bisectors, angles of given measures, and parallel lines. Following each step carefully ensures accuracy. These skills form the foundation for advanced geometry in higher classes.
Chapter-end quiz
4 MCQsOption tap karo — turant pata chalega sahi ya galat, explanation ke saath.
Q1.Which tool is used to draw a circle of a given radius?
Q2.The perpendicular bisector of a line segment meets it at what angle?
Q3.An angle bisector divides a given angle into how many equal parts?
Q4.To draw a line parallel to a given line, which pair of tools is most commonly used?
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