Question

which congruency theorem can be used to prove that △ghl≅△khj?
sss
asa
sas
aas

Explanation:

Step1: Identify vertical - angles

$\angle GHL$ and $\angle KHJ$ are vertical angles, so $\angle GHL\cong\angle KHJ$.

Step2: Observe marked equal - sides

There are two pairs of marked equal sides: $GH = KH$ and $LH=JH$.

Step3: Recall congruency theorem

The Side - Angle - Side (SAS) congruency theorem states that if two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle, then the two triangles are congruent. Here, the included angle between the pairs of equal sides in $\triangle GHL$ and $\triangle KHJ$ is the pair of vertical angles. So, $\triangle GHL\cong\triangle KHJ$ by SAS.

Answer:

C. SAS