Which theorem is it?

Answer choice below in the picture:

None of the above

Step-by-step explanation:

The figure3 shows 1 side and 1 angle of one triangle congruent to 1 side and 1 angle of the other triangle. We are not shown anything else, so the answer is:

None of the above

and you can't prove the triangles congruent.

proofs involving isosceles triangles often require special consideration because an isosceles triangle has several distinct properties that do not apply to normal triangles.(more about triangle types) therefore, when you are trying to prove that two triangles are congruent, and one or both triangles, are isosceles you have a few theorems that you can use to make your life easier.

step-by-step explanation:

an isosceles triangle has two congruent sides and two congruent angles. the congruent angles are called the base angles and the other angle is known as the vertex angle. ∠bac and ∠bca are the base angles of the triangle picture on the left. the vertex angle is ∠abc