In a previous assignment, you create three images.
Combine those three into a single, perfectly aligned image as shown below:
My advice would be to create the combined image using PowerPoint, which makes it easy to resize and align images exactly. Once you have the PoweerPoint slide, display it full screen and record a screen shot to create the final, composite image.
Post that image on your blog and turn in a printout of the blog post. (If you do this with a partner, put the image on both of your blogs, but only turn in one copy of the composite image).