Answer:
229
Step-by-step explanation:
Area of square is = 20 * 20 = 400
radius = 20 / 2 = 10
Area of semi circle is = 1/2 * πr²
= 1/2 * 3.14 * 10²
= 1/2 / 314
= 157
assume there are four shaded regions for the figure
Area of 4 semicircles−Area of shaded region=Area of square ABCD
Area of shaded region=Area of 4 semicircles−Area of square ABCD
= 4 * 157 - 400
= 628 - 400
= 228
so each single shaded area is 228/4
= 57
now in your problem there are 3 shaded regions like this
so area of unshaded region is =
Area of square - 3 * shaded region area of one region
=> 400 - 3 * 57
=> 400 - 171
=> 229
