a)ducem CD_I_AB
AB=L=latura triunghiului echilateral ABC
CD²=L²-(L/2)²=3L²/4
CD=L√3/2
2,25=L√3/2
AB=L=2,25×2/√3=4,5√3/3=1,5√3=3√3/2
b)Atriunghiului ABC=Atriunghiului =3√3/2 × 2,25/2=6,75√3/4≈2,92 m²
Afete laterale=3 × 4 x 3√3/2=18√3=31,14 m²
Atotala=31,14+2,92 × 2=36,98 m²
36,98 × 10%=3,70 m²
36,98+3,70=40,68 m²
c) 40,68 x 20 =813,6 lei
a)
BM=BC/2=20/2=10
AM=√(AB²-BM²)=√(26²-10²)=√(676-100)=√576=24 cm
b)Aplacii= 20 × 24 /2=240 cm² =2,4 dm²
2,4dm² x20 g/dm²=48 g
c) GM=AM/3=24=8
BG=√(GM²+BM²)=√(8²+10²)=√(64-100)=√164=2√41 cm
