Tolong dijawab yang benar yaa.. nanti aku follow... plisss

[tex] k = 2 \: (p + l) \\ 84 = 2 \: (1 \frac{1}{2} l + l) \\ 84 = 2 \: ( \frac{3}{2} l + l) \\ 84 = 2 \: ( \frac{3}{2} l + \frac{2}{2} l) \\ 84 = 2 \times \frac{5}{2} l \\ 84 = 5l \\ l = \frac{84}{5} \\ l = 16.8 \: cm\\ \\ p = \frac{3}{2} \times 16.8 \\ p = 25.2 \: cm\\ \\ L = p \times l \\ L = 25.2 \times 16.8 \\ L = 423.36 \: cm {}^{2} [/tex]