Geometry plz help
posted by Ryan .
A rectangular solid has a top face with surface area of 28 ft, a front face with surface area of 20 ft, and a side face with surface area of 70 ft. What is the volume of this solid?

There are two ways to approach the problem:
1. Calculate the side lengths, a,b and c.
ab=28....(1)
ac=20....(2)
bc=70....(3)
Therefore by dividing ac by bc, we get
a/b=2/7
substitute a=2b/7 into equation (1) gives 2b/7*b=28 => b²=98 => 7√2
You can calculate similarly the other sides.
2.
You are looking for the product abc, from which ab=28
So
abc=ab*bc*√((a/b)/ab)
All the products are known, the quotient has been calculated in part 1.
So the volume abc can be calculated directly. 
umm still lost.....

Did you try method 1 or method 2?
Respond to this Question
Similar Questions

MATHS
Hi Just checking The area of one face of a cube is 64cm squared What it the total surface area of the cube? 
MathVolume and Surface Area
The volume of a cube is 125 cubic inches. Find the surface area. I know that the volume formula is V=Bh where v=volume, B=area of the base, and h=height. How do I get the surface area though? 
Math
A rectangular prism has a volume of 960cm. It's width, length, and height are in the ratio 3:5:8. A) Determine the dimensions of the prism B) What is the ratio of the left side to the front to the top of the prism by surface area? 
geometry
The volume of two similar solids is 1331 m3 and 729 m3. The surface area of the larger solid is 605 m2. What is the surface area, in square meters, of the smaller solid? 
math
Please help with this problem. Compute the following volume and surface area. A rectangular solid has sides of 7 cm, 9 cm, and 11 cm. What is its surface area. ________ square centimeters 
Math
Find the surface area of rectangular pyramids 1. Length= 1.15ft Width=0.82 ft Height of the slanted face =3.17ft Surface Area=7.1879ft^2 Formula for Rectangular Pyramid Surface Area : B+1/2pl B=area of base p=perimeter of base l=height … 
Calculus, Surface Area
An open rectangular box (no top) has a square base with side 10 cm and height 16 cm. The surface area is: 
Math
"An office building is in the shape of a right rectangular prism wit height 200m, length 60m and width 40m. The top quarter of each vertical face of the building is to be covered with a large banner. What is the total surface area … 
science
For this activity, we had to make cube shaped models to represent cells. Then we had to compare aurafve area, volume, and surface area to volume ratio (SA:V) between the cells. Cell A: length of one side=1cm Surface area= 6cm^2 Volume= … 
Science
For this activity, we had to make cube shaped models to represent cells. Then we had to compare surface area, volume, and surface area to volume ratio (SA:V) between the cells. Cell A: length of one side=1cm Surface area= 6cm^2 …