[tex] A_{rectangle} [/tex] = l·w
If 1/6 of the length and width were used for the miniature, we need to multiply both the length and width by 1/6.
[tex] A_{rectangle} [/tex] = [tex] \frac{1}{6} [/tex] l · [tex] \frac{1}{6} [/tex] w
[tex] A_{rectangle} [/tex] = [tex] \frac{1}{36} [/tex] lw
So, the area of the miniature was reduced to [tex] \frac{1}{36} [/tex] of the original area.
720·[tex] \frac{1}{36} [/tex] = 20
Therefore, the area of the miniature is 20 in²