Question

The difference between the circumference and the diameter of a circle is 30cm. Find the diameter of the circle

Answer 1

Answer:

14 cm

Step-by-step explanation:

let the radius=r

diameter=2r

circumference=2πr

2πr-2r=30

2r(π-1)=30

$diameter~2r=\frac{30}{\pi -1} \approx 14 cm$

or

$2r(\frac{22}{7} -1)=30\\2r(\frac{22-7}{7} )=30\\diameter~2r=30 \times \frac{7}{15} =14~cm$