The result is 9 time the original.
As the area of a circle is pi*radius2 the increase in area is a factor of 32. So tripling the radius gives an increase in area by a factor of 9.
The area increases as the square of the radius (or diameter). So if you double the radius you * 4 (quadruple) the area. Treble the radius, you *9 the area.
The area of a circle with a radius of nine centimeters is: 254.5 cm2
Radius 10, area = 100 pi; radius 9, area = 81 pi
When you triple the radius of the circle . . . -- The diameter also triples. -- The circumference also triples. -- The area is multiplied by 9 .
If you triple the radius of a circle, the area will increase by 9. Area is proportional to the square of the radius.
The area increases as the square of the radius (or diameter). So if you double the radius you * 4 (quadruple) the area. Treble the radius, you *9 the area.
The result is 9 time the original.
As the area of a circle is pi*radius2 the increase in area is a factor of 32. So tripling the radius gives an increase in area by a factor of 9.
Radius squared is half of the diameter multiplied by itself. Example: diameter is 6 inches, radius is 3 inches (half of diameter), radius squared is 9 inches (radius multiplied by itself 3 x 3 = 9).
If you are talking about 9 and 12 inch diameter, then divide both by 2 to get the radius. The area of a circle is pi (3.1415 is good for most calculations) multiplied by the square of the radius. So for the 12 inch circle, the radius is 6. The square of the radius is 36, and multiplying this by pi gives approximately 113.1 square inches. Now the 9 inch circle has a radius of 9/2 or 4.5. Squaring this we get 20.25, which multiplied by pi is approximately 63.6 square inches. If 9 and 12 were already the radius in the problem, just don't divide by 2 since you already have the radius.
First of all, there's no such thing as the "area of a circumference". The distancearound the circle is called the "circumference", and the area of the circle is calledthe "area of the circle".-- When the diameter of the circle is doubled, the circumference is doubledand the area is multiplied by 4.-- When the diameter of the circle is tripled, the circumference is tripledand the area is multiplied by 9.-- When the diameter of the circle is multiplied by N, the circumference ismultiplied by N and the area is multiplied by N2 .
Assuming you have a cylinder, the volume is area of the base multiplied by the height. The area of the base is the area of a circle of radius 3 (PI*radius^2 = PI*3^2 = 9*PI). The height is 5. The resulting volume would be 5*9*PI = 45*PI units^3. Did I just do your homework?
A circle with a radius of 9 feet has an area of 254.47 square feet.
The area increases as the square of the radius (or diameter). So if you double the radius you * 4 (quadruple) the area. Treble the radius, you *9 the area.
i believe that it is 18 if the radius is 9 edit: wrong, area = pi*radius^2 so it's 3.1415926535*81=254.469