To determine which theorem can prove that triangle LFK is congruent to triangle KGH, we need to analyze the information given.
From your statement:
- K is the midpoint of LH, which implies that LK = KH.
- Given that H and K are square angles (right angles), we know that angles ∠LKH and ∠KHG are right angles.
- Points F and G are along the lines, and these lines appear to be in the same plane relative to the triangles.
Congruence Conditions Utilized:
- Angle-Side-Angle (ASA): If two angles and the included side of one triangle are equal to two angles and the included side of another triangle, then the triangles are congruent.
- Angle-Angle-Side (AAS): If two angles and a non-included side of one triangle are equal to two angles and a non-included side of another triangle, then the triangles are congruent.
- Side-Angle-Side (SAS): If two sides and the included angle of one triangle are equal to two sides and the included angle of another triangle, then the triangles are congruent.
- Side-Side-Angle (SSA): This condition does not imply congruence of the triangles (the ambiguous case).
- Side-Side-Side (SSS): If three sides of one triangle are equal to three sides of another triangle, then the triangles are congruent.
Conclusion:
In this case:
- We have two right angles (∠LKH and ∠KHG).
- We have the segment equivalency where LK = KH (because K is the midpoint).
Using the SAS theorem:
- Side LK is equal to side KH.
- The included angle between them (∠LKH) is a right angle, which is equal to ∠KHG.
- Applying SAS proves that triangles LFK and KGH are congruent.
Final Answer:
The theorem that will prove that triangle LFK is congruent to triangle KGH is SAS (Side-Angle-Side).