The value of length EF is 2cm
What are congruent triangles?
Congruent triangles are the type of triangles with equal corresponding sides and corresponding angles.
Since HK = 10cm
HG = 4cm
GH = 10-4 = 6
Since EGH is congruent to triangle KGF
angle E = angle K
angle H = angle F
The corresponding line to angle E is HG
and the corresponding line to angle K is FG.
Therefore,
FG = HG
FG = 6cm
The corresponding line to angle H is EG
The corresponding line to angle F is GK
therefore;
EG = GK
EG= 6cm
Therefore;
EF = EG - FG
EF = 6 - 4
= 2cm