In a topographical map of a city, the vertices of the city limits are a (10, 9), b (18, 9), c (18, 2), d (14, 4.5), and e (10, 4.5). the coordinates are measured in miles. what is the area of the city?

The first thing you should do for this case is to draw the ordered pairs in the plane and join the points.
 The area you are looking for is the area of a rectangle plus the area of a triangle.
 Thus, the total area will be
 At = (8) * (4.5) + (1/2) * (4) * (2.5) = 41
 answer
 the area of the city is 41 units^2