Question

cum sa fac ex 4,5/153

Answer 1

4)Suma tuturor unghiurilor dintr-un triunghi = 180°
a) m(<B)=m(<C)=35°
m(<A) = 180-35*2= 180-70=110°
b)m(<B)=48° m(<C)=84°
m(<A)=180-48-84=48°
c)m(<B)+m(<C)=130°
m(<A)=180-130=50°
d)m(<A)=m(<B)=m(<C)
m(<A)=180/3=60°

5)a)AB=AC=BC=9.7cm
Perimetrul = AB+AC+BC=9.7*3=29.1 cm
b)AB=2AC=16cm BC=10.6 cm
AC=AB/2=16/2=8
P=16+8+10.6=34.6 cm
c)AB=0.8(AC+BC)=12 cm
0.8(AC+BC) =12→ AC+BC=12*0.8 = 9.6 cm
P=12+9.6 = 21.6 cm
d)AB+AC=15 cm
   AB+BC=16 cm
   AC+BC=17 cm
   AB=15-AC

15-AC+BC=16
AC+BC=17
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2BC=17+16-15=18
BC=9 cm
AB+BC=18 cm →AB=18-BC=18-9=9 cm
AC+BC=17 cm →AC=17-BC=17-9=8 cm
P= 7+9+9=25 cm