Challenging area question, pls list out all steps

(there are two photo attachments. if you are viewing on the mobile app, view it on the website to see both photos.)

for these questions, i assumed the figure had some symmetric properties.

for the perimeter, see figure 1 attached.
perimeter is around 53.65 cm.



for the difference of the shaded area of a and the sum of the shaded areas of b and c, refer to figure 2 attached.

we first took one side of the square, rotated it until it touched the intersection as shown. this formed both a triangle and a sector of a circle.

we used formulas for those, and then, since it is symmetric (if you do the same thing, you'd get the same result), we found that 

   

then we determined new regions d and e so that we can use subtraction to determine the area of a.

   

the sum of the shades ares of b and c

   

difference between shaded area of a and b+c:

   

22.72 cm²

(i think actual answer without using 3.14 for pi is around 22.796 cm²)