The formula for the area of a rectangle is...
Area = length x width
A = L x W
What we know so far...
Area is 590 cm^2
length is 12 cm
width is unknown
Plug all of these into the equation for area of a rectangle:
590 = 12 * w
or
590 = 12w
Letter A is the correct answer
Hope this helped!
~Just a girl in love with Shawn Mendes