Answer:
A=4cm
ok to do this we do the formula
A=PiR^2
A=3.14*4^2
A=3.14*16
A=50.24
and the area of circle B is 4 times the area of a so
50.24*4=200.96
200.96=3.14*X^2
Since r is on the right side of the equation, switch the sides so it is on the left side of the equation. 3.14 ⋅ r 2 = 200.96 Divide each term by 3.14 and simplify.
r 2 = 64
r=8
CIRLCE A=50.24
CIRLCE B=8