Please jawab nomor 21-24 beserta caranya please cepat

nomor 21 = 2x(p+l) = 2x(27,50+15,75) = b. 86,5 m
nomor 22 = c. 1 dan 3
nomor 23 = 1/2 x 22/7 x 21 x 21 = a. 693 cm2
nomor 24 = sisi miring = 35 cm, keliling segitiga = 42+35+35 = 112 cm, keliling 1/2 lingkaran = 1/2 x 22/7 x d = 1/2 x 22/7 x 42 = 66 cm. jadi 112 + 66 cm = b. 178 cm