Question 1

Unless stated otherwise, use the approximation $\dfrac{22}{7}$ for $\pi$.

2. Calculate, correct to 3 significant figures, the circumference of a circle with: (i) radius 7 cm

(ii) radius 10 cm

(iii) radius 12 cm.

Unless stated otherwise, use the approximation $\dfrac{22}{7}$ for $\pi$.

3. Calculate the length of the arc of a circle if:

(i) the radius is $3.5\text{ cm}$ and the angle at the centre is $60^\circ$, and

(ii) the radius is $6.3\text{ m}$ and the angle at the centre is $120^\circ$.

Unless stated otherwise, use the approximation $\dfrac{22}{7}$ for $\pi$.

4. Find the perimeter of a sector (i.e., the curved portion as well as the two straight portions) of a circle of radius $14\text{ cm}$ and sector angle $75^\circ$.

Unless stated otherwise, use the approximation $\dfrac{22}{7}$ for $\pi$.

5. Find the perimeters of the following shapes (taking the arcs to be quarter or half or three-quarters of a circle, as appropriate) (Fig. 6.14i to 6.14ix):

If the diameter of a car tyre is $56\text{ cm}$, then:

(i) How far does the car need to travel for the tyre to complete one revolution?

(ii) How many revolutions does the tyre make if the car travels $10\text{ km}$?

Find the total perimeter of all the petals in each of the given flowers.

The ratio of the perimeters of two circles is $5 : 4$. What is the ratio of their radii?