For a start i looked into general shape ideas i sketched the out (so that i would have a good reference below are some of the pictures used:
link: http://www.skwirk.com/p-c_s-12_u-214_t-577_c-2141/triangular-prisms/nsw/triangular-prisms/volume-and-surface-area/surface-area
Taken on 18/01/2017
*This image gives a good idea of angles and the shape.
Link:https://owlcation.com/stem/How-To-Work-Out-the-Surface-Area-Of-A-Triangular-Prism-Right-Angled-And-Isosceles
Taken on 18/01/2017
General link for all reference images Found on google: