Calculate the length of a rectangle if its width is 80 mm and its area is 12,000 mm 2.

Brief notation of the problem condition:
Rectangle;
Width – 80 mm .;
Area – 12,000 sq. mm .;
Length =?
Decision:
The area of a rectangle is equal to the product of its width and length. It follows that the length of the rectangle is equal to the quotient of dividing the area by the width. Then:
12000: 80 = 150 (mm.)
Answer: 150 mm.