please tolong dibantu kk beserta caranya

kelilingnya p kan ?
p = πr + 2x + 2y
karena r = x
so
p= πx + 2x +2y
so p = (2+π) x +2y
y= 1/2 ( p-(2+π)x)

luas = 2xy + 1/2 πx^2
masukin y nya
2 x ( 1/2 {p-[2+π]x}) + 1/2 πx^2
= p-(2+π)x +1/2 πx^2

maksimum saat turunannya =0
so
kita turunin
-2-π+πx =0
x = (2+π)/π

kalau masukin nilai π =22/7 didapat
x = (2+22/7)/(22/7)
= 36/7 x 7/22 = 36/22 = 18/11