A runner running in a circular track completes 5 rounds and cover a distance of 2200 m . (a) Write the formula to find circumference of a circle. [1] (b) How much is the length of one round of the truck. [1] (c) Find the length of the diameter of the circle surrounded by the track. (d) Find the area at the circle. [1]

Let's break down the problem step by step. ### (a) Write the formula to find the circumference of a circle. The formula to find the circumference \( C \) of a circle is given by: \[ C = 2\pi r \] where \( r \) is the radius of the circle. ### (b) How much is the length of one round of the track? If the runner completes 5 rounds and covers a total distance of 2200 m, the length of one round (circumference) can be calculated as follows: \[ \text{Length of one round} = \frac{\text{Total distance}}{\text{Number of rounds}} = \frac{2200 \, \text{m}}{5} = 440 \, \text{m} \] ### (c) Find the length of the diameter of the circle surrounded by the track. To find the diameter \( d \) of the circle, we can use the relationship between the circumference and the diameter: \[ C = \pi d \] From part (b), we know the circumference \( C = 440 \, \text{m} \). Therefore, we can rearrange the formula to find the diameter: \[ d = \frac{C}{\pi} = \frac{440}{\pi} \approx \frac{440}{3.14} \approx 140.13 \, \text{m} \] ### (d) Find the area of the circle. The area \( A \) of a circle can be calculated using the formula: \[ A = \pi r^2 \] First, we need to find the radius \( r \). We can find the radius from the diameter: \[ r = \frac{d}{2} = \frac{140.13}{2} \approx 70.065 \, \text{m} \] Now, we can calculate the area: \[ A = \pi r^2 = \pi (70.065)^2 \approx 3.14 \times 4918.24 \approx 15480.57 \, \text{m}^2 \] ### Summary of Answers: (a) \( C = 2\pi r \) (b) Length of one round = 440 m (c) Diameter \( d \approx 140.13 \, \text{m} \) (d) Area \( A \approx 15480.57 \, \text{m}^2 \)