The latest tool I have used is the Ruler tool, under which I used the Polygon setting. This setting allows you to measure multiple points on the map to measure the perimeter and the area of the points. To use this Polygon setting you must use at least 3 points (clicking the map 3 times or more). Odd shapes are no problem and it makes it a lot easier than doing the math manually!
Of course these results, I can not guarantee the accuracy of, but it's close enough for me!
To download Google Earth Pro (for FREE) visit Google's site here: https://www.google.com/earth/desktop/