She would put 0.35 lbs of rice in each bag. Hope it helps!
First you find how much the shape has dilated. To d ok that you divide the size of the size already given to you from the bigger shape from the same did if the smaller shape. So 58÷6=9.7. The shape grew by 9.7. To find x you use the similar side of the other shape again and multiy that size by 9.7. So 9.7×3=29.1
x=29.1
the picture in the attached figure
we know that
area of the triangle is equal to

in this problem
A=47 in²
b=x
h=x
so

therefore
the answer is
x=9.7 in