Page 191 - Start Up Mathematics_5

3. Fill in the blanks.

(a) The line joining two points on a circle is called a _____________.
(b) _____________ is the longest chord of the circle.

(c) Part of the curve between two points on a circle is called an _____________.
(d) Diameter is _____________ times the radius.
4. Radhika drew a circle whose diameter is 4 cm. What is the circumference of the circle?

5. The circumference of a bicycle wheel is 50.22 inches. What is its diameter?

6. What is the circumference of a pizza whose diameter is 30 cm?
7. A circular swimming pool has a radius of 14 m. Find the circumference of the pool.

8. The circumference of a flowerbed is 57 m. Find the diameter of the flowerbed.

SCRATCH YOUR BRAIN

Shweta orders a circular pendant that has an inner and an outer circle. The circumference
of the outer circle is 9 cm and the inner circle is 6 cm. If 42 gems are needed along the
boundary of the outer circle, how many gems of the same size will be needed for the inner
circle?

INDIVIDUAL ACTIVITY

To draw a spiral with the help of a compass

Things We Need: White sheet of paper, a pencil, a ruler and a compass

How To Do:
1. Draw a straight line. With the help of a
compass, draw a small semicircle on this A O B
line. Name the centre as O.

2. Keep the compass at point A and open it
of length AB.
C A O B
3. With A as centre, draw a semicircle on the
other side of the line.

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