7th Grade Math
posted by Daniel .
A pentagonal prism has dimensions that are four times the dimensions of a similar pentagonal prism. So its volume is _____times the volume of the smaller prism.
A) 64
B) 8
C)16
D)4
Would it be A) 64?
Next Question: If the dimensions of a cylinder are doubled the surface area will be _______? Would it be doubled?
Thank you for the help

Volumes are (linear ratio)³ and
areas are (linear ratio)² 
1. V = 2.83*r^2*h.
V1/V2 = 2.83*(4r)^2*4h/(2.83*r^2*h)
V1/V2 = 16r^2*4h/(r^2*h = 64.
2. A1 = 2pi*r^2 + 2pi*r*h
A1 = 2pi*r(r+h)
A2/A1 = (2pi*2r(2r+2h))/(2pi*r(r+h)
A2/A1 = (4pi*r(2r+2h))/(2pi*r(r+h)
A2/A1 = 2(2(r+h)/(r+h) = 4.
2. A shorter Method
A1 = 2pi*r(r+h). Let r = 1, and h = 2.
A1 = 6.28*1(1+2) = 18.84 Sq. Units.
Double r, and h.
A2 = 6.28*2(2+4) = 75.36 Sq. Units.
A2/A1 = 75.36/18.84 = 4.
Respond to this Question
Similar Questions

geometry
the volume of a larger prism is 128 cubic cm. if the prisms are similar with linear ration of 4:3, what is the volume of the smaller prism? 
math
The volume of a larger prism is 168 cubic cm. if the prisms are similar with a linear ratio of 3:2 what is the volume of the smaller prism? 
math
2 rectangular prisms are proportional. the edges of the smaller prism are half as long as the edges of the larger prism. The volume of the larger prism is 1,024 cubic feet. the volume of the smaller prism is what? 
Volume of a rectangular prism
Hello, if the volume of a rectangular prism is LWH = 64 cubic inches, what are the dimensions of a rectangular prism with dimensions twice as long? 
7th grade math
What is the surface area and volume formula of a pentagonal prism? 
math
the dimensions of trianguloar prism A andtriangular prism B are proportional. The volume of the Triangular Prism is 6,400 cubic feet. If the volume of Triangular prism B is 75% of the volume of Triangular Prism B. What is the volume … 
geometry
A right pentagonal prism is 10 cm high. If the area of each pentagonal base is 32 cm squared and the perimeter is 20 cm, what are the lateral and total surface areas of the prism? 
Geometry
A regular pentagonal solid prism has 9cm base edges. A larger, similar solid prism of the same material has 36cm base edges. How does each indicated measurement for the larger prism compare to the same measurement for the smaller prism? 
Geometry
A rectangular prism has a base that is 5 cm by 7 cm and a height of 12 cm. If all dimensions are doubled, what happens to the volume? 
geometry
A rectangular prism has a length of 4.2 cm, a width of 5.8 cm, and a height of 9.6 cm. A similar prism has a length of 14.7 cm, a width of 20.3 cm, and a height of 33.6 cm. The dimensions of the smaller prism are each multiplied by …