Auto recognition of shapes and measuring length and width

[meir]

I'm sure it must be pretty simple but I've been breaking my head over it in the last few days.
Have a set of images with different straight-edged shapes. Running into two issues

1.After I threshold the image I select one of the shapes with the wand. But when I measure it I get the length and width of the bounding rectangle. Isn't there a way for ImageJ to straighten the object and measure it accurately?

2.Is there a way to write a macro that will auto analyze all the images and recognize and measure each shape?

Here is an example image:
http://postimg.org/image/yc78dkxmr/