Question

Polygon B is a scaled copy of polygon A using a scale factor of 5. Polygon A's area is what fraction of polygon B's area

Answer 1

Since, Polygon B is a scaled copy of polygon A using a scale factor of 5.

While doing the scale factor of the length which is in one dimension, we simply multiply the scale factor with the given side to have the length of the newer side.

But while doing the scale factor of the area we multiply length with length. So the scale factor is squared.  

Here, Polygon B is scaled copy of polygon A using scale factor of 5. So the area of polygon B is $5 \times 5$ the area of polygon A.  

So, the area of polygon B is 25 times the area of polygon A.

So polygon A's area is $\frac{1}{25}$ the area of polygon B.