The teacher will be very surprised to see your correct solution 😉
2 / ___ \ 2 2 |\/ 5 *b / ___ \| / / ___\\ /b / ___ \\ |------- + 4*\\/ 3 + 3/| = \b + 6*\1 + \/ 3 // + |- + 2*\\/ 3 + 3/| \ 2 / \2 /
(sqrt(5)*b/2+4*(sqrt(3)+3))^2 = (b+6*(1+sqrt(3)))^2+(b/2+2*(sqrt(3)+3))^2
192 + 96*sqrt(3) + 5*b^2/4 + 4*b*sqrt(15) + 12*b*sqrt(5) = (b+6*(1+sqrt(3)))^2+(b/2+2*(sqrt(3)+3))^2
(sqrt(5)*b/2+4*(sqrt(3)+3))^2 = 144 + b^2 + 12*b + 72*sqrt(3) + 12*b*sqrt(3) + (b/2 + 2*(sqrt(3) + 3))^2
(sqrt(5)*b/2+4*(sqrt(3)+3))^2 = 144 + b^2 + 12*b + 72*sqrt(3) + 12*b*sqrt(3) + 48 + 6*b + 24*sqrt(3) + b^2/4 + 2*b*sqrt(3)
-18*b - 14*b*sqrt(3) + 4*b*sqrt(15) + 12*b*sqrt(5) = 0
-18*b - 14*b*sqrt3 + 4*b*sqrt15 + 12*b*sqrt5 = 0
b = 0 / ((-18*b - 14*b*sqrt(3) + 4*b*sqrt(15) + 12*b*sqrt(5))/b)