please jwb untuk besok no 24

K = AB + BC + CD + DA
240 = 40 + 2x + 8 + 2x + 8 + 40
240 = 96 + 4x
240 - 96 = 4x
144 = 4x
144 : 4 = x
36 cm = x

½x + 23 = ½(36) + 23 = 18 + 23 = 41 cm (C)

AD = 1/2 BC
40 = 1/2×(2x+8)
40 = x + 4
x = 40-4
x = 36
1/2x + 23 = 1/2×36 + 23
= 18 + 23
= 41