R = radius of big circle, r = radius of little circle Area of circle = pi x R x R = 4 x pi x r x r = 4 x pi x 3 x 3 Therefore R x R = 36 and so R = 6 inches
Three
The circumference of a circle with a radius of 10 inches is about 62.83 inches.
A circle with a radius of 8 inches has a circumference of 50.27 inches.
A circle with a circumference of 25 inches has a radius of about 3.979 inches.
The area of a circle if the radius is 2.5 inches is: 19.63 square inches.
The radius of a circle with an area of 35 square inches is 3.34 inches.
6
6 inches pi*32 = 9*pi square inches (smaller circle) pi*62 = 36*pi square inches (larger circle)
Larger than a whale yet smaller than an ant
An annulus. Area = pi (R2 - r2) when R is radius of larger circle and r is radius of smaller circle.
if the radius is a third then the area is a ninth 60.84 x 1/32 = 6.76 timmespi (if that's 'times pi' then) 6.76/pi = 2.15
We can look at total areas (and ignore units-they're all the same). The smaller circle has an area of 9pi, and the larger circle has an area of 25pi. The smaller circle is entirely inside of the larger circle. So anything not in the smaller circle is in the larger circle. 16pi square centimeters are part of only the larger circle. 16pi/25pi=.64. So the desired probability is .64.
The radius is 8 inches.
A circle with a radius of 72 inches has a circumference of 452.39 inches.
The circumference of a circle with a radius of 4.246 inches is about 26.68 inches.
The circumference of a circle with a radius of 10 inches is about 62.83 inches.
A circle with a radius of 9 inches has a circumference of 56.55 inches.
A circle with a radius of six inches has a circumference of 37.7 inches.