Find the circumference and area of the circle whose radius is given 9cm... plz help me!!!?
829290
2 X pi X  r = cirumference\n\npi X r squared = area
915477
PI is not spelled like the pie you eat. \n\nThe area of a circle is found by multiplying pi (3.14) by the radius squared. The radius is half of the diameter so it is 3. the radius squared is 9, so multiply that by pi and get 28.26\n\nthe area is 28.26 square meters
50370
Draw a circle.  From the centre point to the edge draw a straight line.  This is the radius.  The area of a circle is pi times (radius squared.)  The Perimetre of a circle is 2 times pi times radius.
174111
Diameter is 8\nRadius is 8/2, or 4\n\nCircumference is 2 * pi * r = 2 * pi * 4\n\nANSWER : 8 pi\n\nEDIT : No, I'm pretty sure I'm right. I googled and found this (http://mathforum.org/library/drmath/view/57735.html) : "The circumference of a circle is pi times the diameter, so the diameter can be found by circumference/pi = diameter."\n\nSince the diameter is 8, the circumference is 8 pi.\n\nEDIT : Thanks, Mike! :)
598391
First find the area of the circle that is on the top or bottom of the cylinder. The area formula for a circle is \n\n"pi,r squared. That means multiply pi times the radius of the circle which you have to square first.\nThen you take the number that you get and multiply it by the height of the cylinder.\nGood luck.
513696
The area equation of a circle is pi r^2. And, a circle has an arc measure of 360. Since the shaded region has that of 40, it would be 40/360 = 1/9 of a circle.\nA = 1/9 pi r^2 = 59\npi r^2 = 59 x 9\nr^2 = 59x9/pi\nr = sqrt 59 x 9/pi = 13! =)
492563
This cannot be the whole question.  Since you are using the letters r and d, I will assume you are talking about radius and diameter.\nAre you trying to find the area? then use the formula\nA = Pi*r^2\nIf you are trying to find circumference, then use\nC = 2*Pi*r\nRemember that d = 2r (diameter is twice the radius)
970313
r=radius\nd=diameter\n\n1 C=2r(pi)\n2 C=d(pi)\n\n(Same thing because 2r=d)
1117068
Jane and David are calculating the AREA of that circumference. Seinchin, OMG and Paul are correct. Their answer of 8pi is the right one.\n\nEDIT: for the girl who called retarded to someone... mmm.. no. For the person who asked this question: just check the units in the answer. If we are talking about centimeters, your answer MUST be in centimeters and NOT in squared centimeters.
952353
The curved surface area is 2*pi*r*h\n\nor 2*3.142*27*12 sq cms\n\nand 2*3.142*17*35 sq mms\n\nyou can do the rest
763400
Circumference = 2*PI * r\n\nTherfore : Circumference / r = 2 * PI \n\nPI is nominally equal to 3.14
1032048
The answer is 26.17\n\nR^2 (x/2)= Area \n\n Where R is the radius and x is the angle in radians\n\n2(pi/3)= 2.09  \n\n 5^2(2.09/2)=26.17
926424
The diameter of the circle is the diagonal of the rectangle (as the angle in a seicircle is always 90°)\n\nDiameter = 2 * radius\n= 10 cm\n\nSo by Pythagoras' rule\n\nx² + 8² = 10²\nx² = 100 - 64\n= 36\nx = √36\n= 6\nSo other side is 6 cm
480203
Area of a circle = pi*r^2\n\nr=radius os the circle
762697
The aswer to this question is really quite easy. \n\nSince we know that the shaded area is a square, finding its area is a simple matter.  Its area is s^2, or s squared, where s is the length of one edge of the square.\n\nTo find the area of the circle, we use the fact that for any circle, its area is  A = pi x r^2, or pi times r squared, where r is the radius of the circle.  To find a circle's radius, measure from the circle's center to any point on the circumference of the circle.  Multiply r by itself.  Then multiply that result by pi.  That gets you the area of the circle.\n\nWhat you seem to be looking for is the shaded area of the square remaining after removing the area of the circle.  To do this, simply subtract the area of the circle from the area of the square.\n\nYour formula should look something like this:\n\nA (shaded) =  A (square) - A (circle) \n                   =  s^2 - (pi x r^2)\n\nNotice that it does contain the constant pi.\n\nIf your circle is tangent to all sides of the square in which it is inscribed  (a single point on the circumference of the circle touches each side of the square at its mid-point), then your job is made easier still.\n\nA circle tangent to a circumsribed square (in this case a square constructed outside of the circle) has a radius equal to half the length of a side of the square.\n\nThen the above formula collapses to:\n\nA (shaded) = s^2 - (pi x (s/2)^2)\n                   = s^2 - (pi x (s^2/4))\n                   \nNote s^2/4 is read s squared divided by four.\n\nFactoring out common factors, we get \n\nA (shaded) =  s^2  x  (1)  -  s^2  (pi/4)             \n                   =  s^2  x  (1 - pi/4)\n\nNote that pi/4 is less than 1, so (1 - pi/4) is a positive number.\n\nHope this helps.
323605
Area of a circle = pi x r^2 =3.1416 x 4^2=50.265 cm^2\nArea of a circle = pi x (d^2)/4 = 3.1416 x (8^2)/4 = 50.265 cm^2\n\nCircumference of a circle = pi x diameter = 3.1416 x 8 =25.133 cm\nCircumference of a circle = pi x 2 x radius = 3.1416 x 2 x 4 =25.133 cm
522790
Circumference = 2*radius*pi\n\nTherefore, the radius is 30\n\nand the diameter is 60..\n\nHope that helps...