1. ## Geometry homework help. PLEASE

http://i40.tinypic.com/dooq2o.jpg
Can anyone please show the work on how to do this, with the answer because no one in my family knows.

And also.

1.A __ prism has lateral faces that are perpendicular to the two bases.

2.You can determine the __ of an irregular shaped object by measuring its displacement.

3.The volume V of a sphere of radius r is given by the formula V=

4.The __of a pyramid are the faces of the pyramid that are not the base.

2. ok
number one is right prism
number two is volume
number 3 is (4/3) pi r^3
number four is side length

3. Hello darknightcat
Originally Posted by darknightcat
http://i40.tinypic.com/dooq2o.jpg
Can anyone please show the work on how to do this, with the answer because no one in my family knows.
Assuming that the dimensions on the diagram are in cm, the solid is a hollow cylinder of length 7 cm and internal and external radii 4 cm and 8 cm, respectively. Its cross-sectional area is therefore:
$\pi8^2 - \pi4^2$
$=48\pi$
and its volume is:
$7\times 48\pi$
$\approx 1056 \text{ cm}^3$
The density is the mass divided by the volume. So its density is:
$\frac{1144}{1056}\approx1.08\text{ gm/cm}^3$
4.The __of a pyramid are the faces of the pyramid that are not the base.
The missing words are: 'lateral faces' or 'slant faces'