To solve this, first we'll find the area of the rectangle A,
Area=length × width ?=24m×20m 480m=24m×20m 480m squared=area of the rectangle A
now we'll find the width of rectangle B, "the width of rectangle B is 12 meters less than the width of rectangle A", 20m-12m= 8m 8m=width of rectangle B
finally we'll find the length of rectangle B, area of the rectangle B= 480msquared width= 8m length=? (to find this divide the area by the width) 480÷8=60m length of the rectangle B=60m