8. Since A F is perpendicular to J K, you know angles J A F and K A F are congruent (both are right angles). Since A F bisects J K, you know the lengths of J A and K A are the same. Side A F is incident to both triangles, and of course the lengths A F = A F. So we have two side-angle-side triangles, and by the SAS postulate we have triangles J F K and K F A congruent to one another.
9. Yes. The corresponding sides in both triangles have the same lengths. (S K to K F; S J to F J; J K to itself) The claim then follows from the SSS postulate.
