Option D:
[tex]\triangle K L M \cong \triangle K L M[/tex]
Solution:
Reflexive property of congruence:
Reflexive property of congruence means the geometric figure is congruent to itself.
Option A: If [tex]\triangle K L M \cong \triangle P Q R \text { and } \triangle P Q R \cong \triangle S T U \text { , then } \triangle K LM\cong \triangle S T U[/tex]
From the definition of reflexive property, it is not true.
This is transitive property of congruence triangles.
Therefore it is false.
Option B: [tex]\text { If } \triangle KL M \cong \triangle P Q R \text { , then } \triangle P Q R \cong \triangle S T U \text[/tex]
From the definition of reflexive property, it is not true.
Therefore it is false.
Option C: [tex]\text { If } \triangle K L M \cong \triangle P Q R \text { , then } \triangle P Q R \cong \triangle K L M[/tex]
From the definition of reflexive property, it is not true.
Therefore it is false.
Option D: [tex]\triangle K L M \cong \triangle K L M[/tex]
Here, ΔKLM is congruent to itself.
This statement illustrates the reflexive property of congruence for triangles.
Therefore, it is true.
Hence option D is the correct answer.
