Question

stie cineva????????? ​

Answer 1

Explicație pas cu pas:

Triunghiul ABC dr.=>

tgC=tg30=V3/3 =AB/18 => AB=6V3cm

=> (T 30 60 90) BC=2AB=> BC=12V3cm

A=AB×AC/2=3V3 ×18=54V3cm²

P=12V3+6V3+18=18V3+18=18(V3+1)

AD inaltime =>

AD=AB×AC/BC ("Teorema a 2 a a inaltimii pe scolareste) => AD=6V3×18/12V3=> AD=9cm

BE bisect. => T.B AE/EC=AB/BC =>

AE/EC=1/2 => AE=k si EC=2k =>

AC=3k=18 => k=6 =>AE=6cm

Cum mB=60 si BE bisect B => mEBA=30

In triunghiul AEB dr => sinABE=sin30=

1/2=AE/EB => EB=12cm