Gimana caranya yg no 3 nanti dapat pahala kasih jawaban terbaik ya

5:3
keliling = 2 (p+l)
500 = 2 (p+l)
500/2 = p + l
250 = p + l

p = 250/8 x 5
p = 156.25
l = 120/8 x 3
l = 93.75

pembuktian:
keliling = 2 x (p+l)
500 = 2 x (156.25 + 93.75)
500 = 2 x 250
500 = 500

luas = p x l
luas = 156.25 x 93.75
luas = 14648.4375

5*500/3= 8,33 maaf kalo salah