B U N Ă!
u-unitate de măsură
a) Perimetrul tr. ABC.
BC²=(xB-xC)²+(yB-yC)²
BC²=(-2-0)²+(0-4)²
BC²=(-2)²+(-4)²
BC²=4+16
BC²=20
BC=2√5u
AB²=(xA-xB)²+(yA-yB)²
AB²=25
AB=5u
AC²=(xA-xC)²+(yA-yC)²
AC²=25
AC=5u
P∆ABC=AB+AC+BC=5+5+2√5=(10+2√5)u
b) Aria triunghiului ABC.
Oy /_ Ox => CO/_AB => CO- înălțimea ∆ABC
CO=|4|=4 u
[tex] A = \frac{l \times h}{2} = \frac{AB \times CO}{2} = \frac{5 \times 4}{2} = \frac{20}{2} = 10 {u}^{2} [/tex]
#Kawaiimath
