No 22 gimana kak, tolng y

Keliling = π x d
88 cm = 22:7 x d
88 x 7 : 22 = d
28 = d
r = d : 2
r = 28 : 2
r = 14

Luas = π x r x r
Luas = 22 : 7 x 14 x 14
Luas = 616 cm^2 d.