Construction of Lines
Steps to construct a line segment of length 5 cm:
1.Draw line l.
2.Mark a point on line and name it P.
4.Place the pointer of the compass on point P.
6.PQ is the required line segment of length 5 cm.
Two lines are said to be perpendicular when they intersect each other at an angle of 90o.
The perpendicular bisector is a perpendicular line that bisects another line into two equal parts.
Constructing of Angles
An exact copy of a line segment can be constructed using a ruler and a compass.
To construct a copy of an angle:
- Draw a line AB.
- Mark any point O on AB.
- Place the compass pointer at vertex X of the given figure and draw an arc with a convenient radius, cutting rays XY and XZ at points E and F, respectively.
- Without changing the compass settings, draw an arc on line AB from point O. It cuts line AB at P.
- Set the compass to length EF.
- Without changing the compass settings, draw an arc from P cutting the previous arc at point Q.
- Join points O and Q.
- Hence, ∠POQ is the required copy of ∠YXZ.
To construct the bisector of an angle:
Let the given angle be LMN.
Place the compass pointer at vertex M of the given angle.
Draw an arc cutting rays ML and MN at U and V, respectively
Draw an arc with V as the centre and a radius more than half the length of UV in the interior of ∠LMN.
Draw another arc with U as the centre and the same radius intersecting the previous arc.
Name the point of intersection of the arcs as X.
Join points M and X.
Thus, the ray MX is the required bisector of ∠LMN
Steps to construct a 60° angle:
- Draw a line.
- Mark point P on the line.
- Draw an arc from point P with a convenient radius cutting the line at a point.
- Name the point of intersection of the arc and the line as Q.
- Draw another arc with Q as the centre and the same radius so that it passes through point P.
- Name the point of intersection of the two arcs as R.
- Join points P and R.
In a similar way, we can construct:
A 900 angle without using the protractor
A 1200 angle without using the protractor
With our free PDF notes you can get success in any competitive or entrance exams like CTET, KVS, NET, CAT, MAT, CMAT, SSC, B.ED, IBPS Recruitment, IAS, CSAT, State Civil Services Exams, UPTET, PSTET, HTET & many more. It also provides NCERT solutions, CBSE, NTSE, Olympiad study material, Indian General Knowledge, English Grammar, Hindi, Mathematics Tricks, Current affairs, Science, S.ST, model test papers, important Question.