Question

Chris used 45 meters of fencing to enclose a circular garden. What is the approximate radius of the garden,rounded to the nearest tenth of a meter? Use 3.14 for π

Answer 1

We are given the circumference of the circle. The formula for circumference of a circle is C = 2πr, where r is the radius of the circle. Since we want to find r, we can isolate it in the formula.

C = 2πr

Divide both sides of the equation by 2π to isolate the variable.

C / 2π = r

r = C / 2π

The circumference is given as 45 metres. Substitute this into the formula and solve.

r = 45 / 2π

r = 45 / 2(3.14)

r = 45 / 6.28

r = 7.2

Answer:

7.2 metres

Answer 2

The length of the fencing corresponds to the length of the perimeter of the garden:
$p=45 m$
We also know that the perimeter of a circle is given by:
$p=2 \pi r$
where r is the radius of the circle.

Putting together the two equations, we have
$2 \pi r = 45$
from which we can find r, the radius of the garden:
$r= \frac{45}{2 \pi}= \frac{45}{2 \cdot 3.14}=7.17 m$