jawab pakai caranya yaa! pliss secepatnya

a = 20
b = 20 + (9 x 2) = 20 + 18 = 38
t = 12
[tex]l = \frac{(a + b) \times t}{2} = \frac{(20 + 38) \times 12}{2} = 58 \times 6 = 348 \: cm {}^{2} [/tex]
jadi jawabannya A