Question

repede !! va rog !! coroana !!!

Answer 1

1)a)∆ADB tr.dreptungic(.1)
AD=DB=x(2)
Din (1) si (2) rezulta ca ∆ADB=∆ dr.is.=>
AB=AD√2=x√2

∆BAC=tr.dr cu BA=AC=>∆BAC=∆dr.is
=>A∆BAC=cat•cat/2=
=(x√2•x√2)/2=x²•2/2
A∆BAC=x² m²

A∆ABC+A∆ADB=
AB•AC/2+BD•DB/2=
x√2•x√2/2+x•x/2=
2x²/2+x²/2=
=3x²/2
=1,5x² m²
b)A∆ADB+18=A∆BAC
BD•AD/2+18=AB•AC/2
x•x/2+18=x√2•x√2/2|•2
x²+36=2x²
36=2x²-x²
x²=36
x=√36=6 m

c)AD=6 m
BC=AB√2=AD√2•√2=6•2=12 m=120 cm
120:30=4
4+1=5 lalele trebuie plantate