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\\November 3, 2023 11:36 AM Surender Prajapati Proof 5 Reader _________________________ Date: ___________________74

DRAWING A CIRCLE USING COMPASS

Let us draw a circle of radius 4 cm.

Step 1: Fix a sharp pencil in the pencil holding arm of a compass
firmly.

Step 2: Put the metal tip of the compass on the ruler at 0 and open
out the arm of the compass in such a way that its pencil tip
rests on 4-cm mark on the ruler.

Step 3: Now, take a point O on the sheet of paper. Keep the metal tip
of the compass firmly at O.

Step 4: Now, hold the head of the compass firmly and move the pencil
point around the point O to trace a circle of radius 4 cm. 4 cm

MEASURING THE CIRCUMFERENCE OF A CIRCLE WITH THREAD

We cannot measure the circumference of a circle by a ruler because it is a curved path.
We can measure the circumference of a circle by using a thread. A

Step 1: Draw a circle of suitable radius (say 3 cm).
Step 2: Mark a point A on the boundary of the circle.
Step 3: Place one end of a thread on A and hold it firmly.

Step 4: Gently, take the thread around the circle till you reach the
point A again.
Step 5: Make a mark on the thread which lies on A after the complete
round.
Step 6: Now, measure the thread using a ruler. This gives the
circumference of the circle.

Practice Time 7F

1. Observe the figure given alongside and fill in the blanks.
(a) The centre of the circle is ______. P R

(b) The diameter of the circle is ______. A M N D
(c) ______, ______ and ______ are the radii of the circle. O
(d) The chords of the circle are _______ and _______. B

(e) The points ________, ________, ________, ________ and C Q
________ are on the circle.
(f) The points ________ and ________ lie on the exterior of the circle.

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