It might be, but we can't see the tails. The anal scutes on the left one look very male, but the anal scutes on the right look very immature, and have not started to take on an adult shape. This right one could go either way.
Regardless of sexes, they should not be kept as a pair, so I'm hoping you will have two separate enclosures.
http://www.tortoiseforum.org/thread...n-bullying-aggression-behavior-issues.139589/
http://www.tortoiseforum.org/thread...together-a-lesson-learned-the-hard-way.94114/
http://www.tortoiseforum.org/threads/bad-day-for-baby.114328/
http://www.tortoiseforum.org/threads/pairs.34837/
Read these threads for more explanation, but basically: Two males will fight, in a male/female pair the male will usually harass the captive female to death, and in a female/female pair, one female will be dominant and try to run the other one out of its territory. Groups of one male and several females will usually work, but pairs almost never work.
Male and Female all the way