Question

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Answer 1

Zad. 6

a) H=8 r=6

Pc = Pp + Pb = π*r2 + π *r * l

Pp= π*r2 = 36π

Pb = π *r * l =60π

l2= H2 + r2

l2= 82 + 62

l2 = 64 + 36

l2= 100

l =10 

Pc =36π + 60π = 96π 

 

b) H=?  r=10/2 = 5  l = 7

Pc = Pp + Pb = π*r2 + π *r * l

Pp= π*r2 = 25π

Pb = π *r * l = 35π
Pc =25π + 35π= 60π [j]  

 

c) H=6  r=4√3/2 = 2√3 

Pc = Pp + Pb = π*r2 + π *r * l

Pp= π*r2 = 12π

Pb = π *r * l = 12√12π

l2= H2 + r2

l2= 6² + (2√3)²

l2 = 36 + 12

l2= 48

l = √48

 

Pc =12π + π2√3 *√48 [j] = 12π + 24π = 36π

Zad. 7

Trójkąt równoramienny czyli  

 

Pc = Pp + Pb = π*r2+ π *r *
l=6 cm
2r=6 cm
r=3 cm
h=6√3/2=3√3 cm

Pc=πr²+πrl
Pc=π*3²+π*3*6
Pc=9π+18π
Pc=27 π cm²= 84,8 cm²

 

 

Zad. 8  

Pc = 80π r = 4 l = ?

Pc = π*r2+ π *r * l

80π = 16π + 4π*l

64π = 4π*l    /:4π

l = 16

Odp. Długość tworzącej stożka wynosi 16.