Congruent means that the measures of both triangles are the same or in other words the corresponding sides and angles equal each other. The measurements will be the same. Here, bc corresponds to fg(gf), ab to ef and ac to eg. This means that those sides have equal measures or in other words equal each other. BC=8 as GF equals 8 other two sides, EF=6 as AB equals 6 and the same thing for the last side EG=10 as AC equals 10. Hope this helps.
