Examples for different flare-ribbon morphologies in AIA 160 nm images. Top panel: M6.3 two-ribbon flare on November 1, 2013 at 19:55 UT, about 2 minutes after the GOES SXR peak. This is an example of a two-ribbon morphology where ribbons can be seen to open up toward the east. Middle panel: M2.9 circular-ribbon flare on October 16, 2010. The image was taken at 19:16 UT, about 4 minutes after the peak. The circular ribbon can be seen in the left half of the image, encompassing a dot-like ribbon. To the right, a weaker remote ribbon can be observed as well. Bottom panel: X1.5 complex-ribbon flare on March 9, 2011 captured at 23:29 UT, about 6 minutes after the peak. It reveals no clear shape that could be classified as either a two-ribbon or circular-ribbon morphology.