The table below A
3. Circle A has been enlarged to create circle
shows the circumference of both circles.
Circumference
Circle Circumference (inches)
2
5
A
6
A
15
O
1.5
Based on the information in the table, what scale factor was used
9
A
to create circle
?
O
2.5
CLEAR ALL

Step-by-step explanation:

See attachment for proper presentation of question.

From the attachment, we have:

Required

Determine the scale factor

To solve this, simply divide the circumference of A' by that of A.

This gives the scale factor used

i.e.

Substitute values for A and A'

Hence, the scale factor used is 1.5

Additional Note:

If the given parameters had been the area of A and A', you'll need to first solve for the radius of both circles.

Then determine the scale factor by A'/A

geometry: triangles

solvers

lessons

answers archive

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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