Question

Calculati perimetrul triunghiului ABC,daca: a)AB=AC=BC=9,7cm; b)AB=2AC=16cm, BC=10,6cm; c)AB=0,8(AC+BC)=12cm; d)AB+AC=15cm,AB+BC=16cm,AC+BC=17cm.

Answer 1

a) P=AB+AC+BC=9,7x3=29,1 cm

b) P=AB+AC+BC=2AC+AC+BC
2AC=16 cm
AC=16:2=8 cm
P=16+8+10,6=34,6 cm

c) P=AB+AC+BC=12+AC+BC=12+15=27 cm
AC+BC=12:0,8=15

d)AB+AC=15cm⇒AB=15-AC
AB+BC=16cm
AC+BC=17cm⇒BC=17-AC
15-AC+17-AC=16
32-16=2AC
2AC=16
AC=16:2
AC=8 cm
AB=15-8=7 cm
BC=17-8=9 cm

P=AB+AC+BC=7+8+9=24 cm