Question

Urgentttt pleaseeeeeeeee

Answer 1

18 )

Al=30πcm²
V=45πcm³

Al=2πRh
V=Ab*h ⇒ πR²*h
At=2πR *( R+h)

30π=2πRh/:π
R*h=30:2
R*h=15 cm

V=πR²h
45π=πR²h/:π
45=R²h
R²h=45
h=15 cm²/2
R²*15 cm²/R=45cm³
15R cm²=45 cm³
R=45:15
R=3cm

b)

h=15cm/3cm
h=5cm

c)

At=2πR(R+h)
At=2π*3cm(5cm+3m)
At=2π*3*8
At=2π*24
At=48πcm²

19)

Notam cu a - Generatoarea
Notam cu b - Raza

a/2=b/3=k

a/2=k
a=2k

b/3=k
b=3k

Al=2πRG
108π=2π*2k*3k
108π=2π*6k²/:π
108=12k²
k²=108:12
k²=9
k=√9
k=3 cm

a=2*3=6cm
b=3*3=9cm

h=6 cm

R=9cm

At=2πR(R+h)
At=2π*9(9cm+6cm)
At=18π*15cm
At=270πcm²

Sper ca te am ajutat!!!