The area of the circle is 9picm^2 or 28.26cm^2. From the perimeter (circumference) of a circle , we can calculate the radius, which we can then use to calculate the area of the circle . The formula for circumference of a circle is: C=2pir, where C=Circumference, and r=radius. Using the given data: 6pi=2pir Cancel the like terms on both sides. 6cancelpi=2cancelpir Divide both sides by 2. 3=r Now that we know the radius is 3cm, we calculate the area with the formula : A=pir^2 A=pixx3^2 A=pixx9 A ... If a,b and c are the lengths of the sides and S is the area of the triangle the radius of the inscribed circle is given by the formula : r=(2S)/(a+b+c) The area S can ... The formula for area of a circle is #pir^2#. Now, let's say circle A has a radius #a#, and circle B has a radius #b#. The area for circle A would be #pia^2# and the area for circle B would be #pib^2#. Area of circumscribed circle is 194.5068 If the sides of a triangle are a, b and c, then the area of the triangle Delta is given by the formula Delta=sqrt(s(s-a)(s-b)(s-c)), where s=1/2(a+b+c) and radius of circumscribed circle is (abc)/(4Delta) Hence let us find the sides of triangle formed by (4,6), (2,9) and (8,4). This will be surely distance between pair of points, which is a=sqrt((2-4)^2+(9-6)^2)=sqrt(4+9)=sqrt13=3.6056 b=sqrt((8-2)^2+(4-9)^2)=sqrt(36+25)=sqrt61=7.8102 and c=sqrt((8-4 ...
