title: How do you determine the upper-left coordinates of a rectangle based on the center coordinates?
body: <p>Based on the coordinate system, how would you determine the upper left coordinates of a rectangle if you are only given the center coordinates of the rectangle and the width and height?</p>
  
  <p>For example, the center coordinates for a rectangle are (40,40) and the rectangle has a width of 90 and a height of 60. </p>