Question

In figura alaturata ,AB\\DE si DF⊥CE .Utilizind datele din desen determina aria triunghiului CDF

Answer 1

AB II DE ⇒ ΔABC ~ ΔCDE
AB/DE=AC/CD=BC/CE
⇔ 13/52 = 15/CD =BC/CE

15/CD = 13/52 ⇒ CD = 52 ×15 /13 = 60

In Δ CDF, dreptunghic in F :
CF² = CD² -DF²
CF² = 60² -48²
CF² = 3600-2304
CF² = 1296
CF = 36

Aria Δ CDF = CF×DF/2 = 36×48 /2 = 864