Question

.....

★871




...................

Answer 1

EC = CD = 2 части
30 = (BE + EC + CD) * 2
3 + 2 + 2 = 7 частей

$BE = 30:14*3=6 frac{3}{7}$ см

$EC = CD =30:14*2=4 frac{2}{7}$ см

$S_{AECD} =(4 frac{2}{7})^2+(6 frac{3}{7}*4 frac{2}{7}):2 = frac{900}{49}+ frac{1350}{98}= frac{3150}{98}= 32 frac{14}{98}=32 frac{1}{7}$ см²