In the given figure, points A, B, C and D are the centres of four circles that each have a radius of length one unit. If a point is selected at random from the interior of square ABCD. What is the probability that the point will be chosen from the shaded region.\
Given: A, B, C, and D are the centers of four circles that each have a radius of length one unit. If a point is selected at random from the interior of square ABCD
To find: Probability that the point will be chosen from the shaded region,
In the figure we can see 4 circles of radius 1 unit.
Area of quarter circle with centre A:
$=\frac{1}{4}\left(\pi r^{2}\right)$
$=\frac{1}{4}\left(\pi \times 1^{2}\right)$
$=\frac{\pi}{4}$
Since all the circles are of the same radius, hence the area of quarter with centre B, C, D will be same as the area of circle of quarter of circle with centre A.
Hence total area covered by 4 quarter circle will be
$=4\left(\frac{\pi}{4}\right)$
$=\pi$ unit $^{2}$
Side of the square will be 2 units
Area of square ABCD = 4 unit2
Area of the shaded portion
We know that PROBABILITY
$=\frac{\text { Number of favourable event }}{\text { Total number of event }}$
$=\frac{4-\pi}{4}$
$=1-\frac{\pi}{4}$
Hence probability of the shaded region is $1-\frac{\pi}{4}$