Linda throws a dart that hits the square shown below: a square is drawn. a circle of radius 9 units touches the sides of the square. what is the probability that the dart hits a point in the circle? 18% 21.5% 78.5% 81%

The picture in the attached figure

step 1
find the area of a square
area of a square=b²
b in this problem is the diameter of a circle
b=2*9------> b=18 units²
area of a square=18²-----> 324 units²

step 2
find the area of a circle
area of a circle=pi*r²
r=9 units
area of a circle=pi*9²------> 254.34 units²

step 3
find the probability that the dart hits a point in the circle
P=area of the circle/area of the square
P=254.34/324------> P=0.785-----> 78.5%

the answer is
78.5%