Demetria is tiling a square area of her bathroom floor. For every 13 white tiles used, she wants to use 12 gray tiles. On the grid, shade the tiles to show a pattern that would match the ratio of white tiles to gray tiles that Demetria would like to use. Then write a ratio to show the relationship between the number of white tiles and the number of gray tiles.

12/11c

or

12

c

11

i believe it is c.y = 9x

rise over run. 9 units up over 1 unit right or 9/1

geometry: triangles

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call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

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