Page 177 - ICSE Math 6

Step 1: Draw line segment PQ.
P Q

Step 2: With P as centre, draw arcs with radius more than half
of PQ on both sides of PQ. P Q

A
Step 3: Without changing the opening of the compass, draw arcs
with Q as centre to intersect the arcs drawn earlier at A
and B. P Q
B

Step 4: Join A and B. Line AB is the required perpendicular A
bisector of PQ.
P Q
B
Use of Protractor to Construct an Angle

Suppose we want to construct an angle of 50°. To do so, follow the steps given below.

Step 1: Draw a ray, say OP, with initial point O.
O P

Step 2: Place the protractor on ray OP such that its mid- Q
point coincides with point O and the base line
coincides with ray OP.

Step 3: The 0° mark of the inner scale falls on ray OP.
Therefore, we will consider the inner scale for O P
constructing the angle. Mark a point, say Q, on Q
the division which represents 50°.

Step 4: Remove the protractor and join O and Q. Thus,
∠POQ is the required angle. O P

To Construct an Angle Equal to a Given Angle A

Let’s draw an angle equal to ∠ABC given alongside. To do so,
follow the steps given below.
B
C
Step 1: Draw ray QR with initial point Q. Q R

A
Step 2: Using a compass, draw an arc of any suitable radius in
∠ABC with centre at B, such that it intersects ray BC E
at D and ray BA at E. B
D C
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