SOLUTION: How to calculate the relative amounts of colour needed for a diamond shape? As part of our assignment we have to create our own design for a quilt and I choose to do a diamond,

Algebra ->  Functions -> SOLUTION: How to calculate the relative amounts of colour needed for a diamond shape? As part of our assignment we have to create our own design for a quilt and I choose to do a diamond,       Log On


   



Question 964200: How to calculate the relative amounts of colour needed for a diamond shape?
As part of our assignment we have to create our own design for a quilt and I choose to do a diamond, but I need to calculate the amount of colour I would need but I do not know how to do it.
The functions that I have used to create the outer diamond are:
y=x+15 (-15< x <0)
y=-x-15 (-15< x <0)
y=x-15 (0< x <15)
y=-x+15 (0< x <15)
These functions are for the inner diamond:
y=x+10 (-10< x <0)
y=x-10 (0< x <10)
y=-5/5x+10 (0< x <10)
y=-5/5x-10 (-10< x <0)

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
I would think that by
y=-5/5x+10 you mean y=-%285%2F5%29x%2B10 , or simply y=-x%2B10 ,
and that by
y=-5/5x-10 you mean y=-%285%2F5%29x-10 , or simply y=-x-10 .
Those equations make a design like this:
showing nested diamonds (or really nested squares).
If calculating areas was necessary, we know that the area of a rhombus is half the product of the diagonal lengths.
So, the area of the large square is %281%2F2%29%2A30%2A30=450 square units,
and the area of the smaller square is %281%2F2%29%2A20%2A20=200 square units.
We could invoke a lot of higher math, but not even the calculation of areas above is necessary to find the ratio of the areas.

I appreciate your effort at using math to describe the design.
without that (or a picture) I would have no idea of what your design was.
The description was complicated, but the calculation is very simple,
as in fifth grade math.

The smaller, inside square's diagonals are 2%2F3 as long as
the larger, outside square's diagonals.
The inside square is a 2%2F3 scaled-down version of the outside one.
Its inside square's sides are 2%2F3 the length of the outside square's sides,
and as a consequence, the inside square's area is
%282%2F3%29%282%2F3%29=4%2F9 the area of the outside square.

If you are going to cut squares in two sizes and sew one on top of another,
for every 9 feet of material for the larger square you will need 4 feet of material for the smaller square.

If, however, you are going to saw 4 trapezoids of the outside color,
forming a frame around the inside square,
that frame will be 1-4%2F9=9%2F9-4%2F9=blue%285%2F9%29 of the area of the large outside square,
and since the smaller inside square has green%284%2F9%29 of the area of the large outside square,
so the ratio of visible material areas is blue%285%29%3Agreen%284%29 in favor of the outside color.