b) it should be noted that the diagonal of the squares X and Y are also the radii of the two respective quadrants. These quadrants are inscribed in their respective squares so the side lengths of the two bigger squares also equals the length of the diagonal, 11.75cm
Perimeter of shaded region = arc length of the semicircle + four side lengths of the bigger squares
= half the circumference of a full circle + four radii
= πr + 4r
= 3.14 x 11.75 + 4 x 11.75
= 83.895
= 83.90cm (to 2 decimal places)