Question

Buna seara, ex 29 va rog 102533 si saoirse1​

Answer 1

ΔDBC - dreptunghic  } => ∡D = 30°

∡C = 60°

Ducem EB ⊥ DC

In ΔDEB

tg30° = EB/DE

√3/3 = 4√3/DE => DE = 12√3/√3 = 12 cm

In ΔBEC

ctg60° = EC/DE

√3/3 = EC/EB => EC = 4√3·√3/3 = 12/3 = 4 cm

DC = DE + EC = 12 + 4 = 16 cm

AB = DE = 4 cm

Lm = (DC + AB)/2 = (16 + 12)/2 = 28/2 = 14 cm