Answer:
40/49
Step-by-step explanation:
probability that a point chosen at random in the given figure will be inside the larger circle and outside the smaller circle = ( area larger circle - area of smaller circle / area of larger circle )
area of a circle = πr² where r = radius
area of smaller circle :
radius = 6
==> plug in 6 for r
A = π(6)²
==> evaluate exponent
A = 36π
Area of larger circle :
Radius = 14
==> plug in 14 for r
A = π(14)²
==> evaluate exponent
A = 196π
We have probability = area larger circle - area of smaller circle / area of larger circle
area of larger circle = 196π
area of smaller circle = 36π
probability = (196π - 36π)/196π
==> subtract 36 from 196
probability = 160π/196π
==> simplify fraction and cancel out π
probability = 40/49
9 x 12 = 108
9 x 6 / 2 = 27
9 x 10 / 2 = 45
108 + 27 + 45 = 180
answer
area = 180 ft^2
