Question

The circumferences of two circles are 66cm and 132cm respectively. Find the difference between their radii​

Answer 1

Answer:

around 11

($\frac{33}{\pi }$ exactly)

Step-by-step explanation:

radius of circle which has a circumference of 132 cm : $r_1$

radius of circle whichhas a circumference of 66 cm : $r_2$

circumference : 2π*(radius)

$2\pi r_1=132\\2\pi r_2=66$

$r_1=\frac{132}{2\pi } =\frac{66}{\pi } \\\\r_2=\frac{66}{2\pi } =\frac{33}{\pi }$

∴$r_1-r_2=\frac{66}{\pi } -\frac{33}{\pi } =\frac{33}{\pi }$

π ≈ 3

$r_1-r_2=\frac{33}{\pi }$ ≈ $\frac{33}{3} =11$