In a grid of a backyard, the vertices of the floor of a shed are (70, 50), (90, 60), (90, 10), and (70, 10). The coordinates are measured in feet. Find the area of the floor of the shed.

Henry's butcher shop uses an electronic scale that measures to 1/100 of a pound. which is the most accurate measurement based on the limitations of the scale that might be found on a package of meat sold by henry?