In order to find the area of a circle, the important thing is to the find the radius first.
Given that the circumference of a circle is 2πr (where r=radius), then
Circle 1: 2πr=25π or r=25/2
Circle 2: 2πr=75π or r=75/2
The area of a circle is πr2. Therefore,
Area of Circle 1: π(25/2)2=625π/4
Area of Circle 2: π(75/2)2=5625π/4
an easy way to do it is to first draw two and a half circles,(circles represent 20s)then first divide the two full circles(not including the half circle).So now we have two 20s.You should know that 10 divided by 2 equals 5 so divide that ten and there you go you have 25 for your answer!
The ratio of their surface areas is 42 to 52 or 16 to 25
The ratio of areas is 18:50 which simplifies to 9:25 or 9/25 So the ratio of their sides is sqrt(9/25) = sqrt(9)/sqrt(25) = 3/5 That is, the linear ratio is 3:5
16:25
4:25
an easy way to do it is to first draw two and a half circles,(circles represent 20s)then first divide the two full circles(not including the half circle).So now we have two 20s.You should know that 10 divided by 2 equals 5 so divide that ten and there you go you have 25 for your answer!
a circle has 4 sides
9:25
The ratio of their surface areas is 42 to 52 or 16 to 25
The ratio of areas is 18:50 which simplifies to 9:25 or 9/25 So the ratio of their sides is sqrt(9/25) = sqrt(9)/sqrt(25) = 3/5 That is, the linear ratio is 3:5
16/25
16:25
4:25
16:25
5:11
-6
If the lengths are in the ratio 3:5, then the surface areas are in the ratio 9:25.