matx is usually 244mm x 244mm.
170mm x 170mm is ITX or mini-ITX.
I think it uses Q57 chipset it may well be to tell for sure measure it
305mm X 244mm for full size ATX standard
but it does not need to be exact
matx performs the same function as atx boards but their stndard size is
170 mm × 170 mm
again size variations exist as long as the mounting hole are the same as ATX