Casper2000
contestada

A right cylinder has radius 9 cm and height 12 cm. If the radius and height are tripled, what happens to the surface area? A. The surface area is multiplied by 9. B. The surface area is multiplied by 6. C.The surface area is multiplied by 1/3. D. The surface area is tripled.

Respuesta :

shoot4damoon
the formula for surface area is 
A= 2[tex] \pi [/tex] rh + 2[tex] \pi [/tex] r[tex] x^{2} [/tex]
The cylinder not trippled 
SA = 1187.52
Trippled 
SA= 10687.7 
 so the answer is A. multiplied by 9
apologiabiology
cylinder surface area (original) =2pir^2+2pirh
if height is trippled and radius is tripple then

new area=2pi(3r^2)+2pi(3r)(3h)
new area=2pi9r^2+2pirh9
new area=9(2pir^2)+9(2pirh)
new area=9(2pir^2+2pirh)
remember that 2pir^2+2pirh=original area
new are=9(original area)

therefor the surface area is multiplied by 9