Answer:
0.19512195122
Step-by-step explanation:
Answer:
Let R = radius of big circle
r=radius of small circle
A1=Area of small circle
A2=Area of big circle
R=9r
A1=50cm^2
A1=pi*r*2
A2=pi*R^2
A2=pi*(9r)^2
A2=81*pi*r^2
A2=81*A1
A2=4050cm^2
Hence the big circle has area of 4050cm^2
Step-by-step explanation:
Answer:
C≈50.13
Step-by-step explanation:
The answer is C≈50.13
Answer:
You'll need 18.85 feet of ribbon.
Step-by-step explanation:
The circumference is 
.
Answer:
Lana is 15 and Susan is 30
Step-by-step explanation:
let Lana's age=x
Susan's age=2x
Their ages four years ago:
Lana=x-4
Susan=2x-4
Now their ages 4years ago was 37 so:
x-4+2x-4=37
3x-8=37
3x=37+8
3x=45
x=15
Since Lana's age is x,she is 15years
Since Susan's age is 2x,she is 30years
