Question

A right cylinder has a circumference of 14π cm. Its height is 3 times the radius. Identify the lateral area and the surface area of the cylinder.

L = 923.6 cm2 ; S = 1231.5 cm2
L = 967.6 cm2 ; S = 1231.5 cm2
L = 294 cm2 ; S = 392 cm2
L = 461.8 cm2 ; S = 967.6 cm2

Answer 1

L=923.6 cm2 ; S =1231.5 cm2

Step-by-step explanation:

L=2πR

L=14π

2πR=14π

R=14π/2π=7 - the radius

h=3R=3*7=21 -the height

S(l)=2πRh=Lh=14π*21=294π≈923,6 - the lateral area

S(s)=2πR²+Lh=2π*7²+294π=2π*49+294π=98π+294π=

=392π≈1231,5 -the surface area