Disclosed herein is a system for joining interlocking panels at a non-linear (i.e. not straight) angle. The system comprises a first interlocking panel comprising an edge having a tongue or a groove, a second interlocking panel arranged at a non-linear angle to the first interlocking panel, and a joining member that is configured to receive the tongue or groove of the first interlocking panel and an edge of the second interlocking panel whereby the first and second interlocking panels are mechanically joined.