Scientist use microscopes to magnify very small objects so they can be seen with the human eye. if a microscope is set to magnification of 10,000 times the size of the object, how long is the actual sample of the cell if it appears to be .743 cm long?

a) 7.4 x 10^ -5
b) 7.43 x 10^ -5
c) 7.43 x 10^ -4
d) .743 x 10^ -5

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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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