Chords of triangle

Project ID: 
3000020220
Question: 

Students were given the following task: In a given triangle $KLM$, with a point $S$ located in its interior, find all chords of the triangle that are bisected by point $S$ (see the picture).

Students started discussing possible solutions:

Paul suggested constructing the chords as line segments perpendicular to the sides of triangle $KLM$, with endpoints on the sides and passing through point $S$.

Radek suggested constructing the chords as line segments connecting point $S$ and the vertices $K$, $L$, and, $M$ of triangle $KLM$.

Ota suggested finding the centroid of the triangle and constructing the line passing through both the centroid and point $S$. The endpoints of the chord are where this line intersects the sides of the triangle $KLM$.

Jane would reflect triangle $KLM$ through point $S$ to get triangle $K'L'M'$. The intersections of the corresponding sides of triangles $KLM$ and $K'L'M'$ would give the endpoints of the desired chord.

Who was correct?

Answer 1: 

Jane

Answer 2: 

Paul

Answer 3: 

Radek

Answer 4: 

Ota

Correct Answer: 
Answer 1
Hint: 

Jane solved the task as follows: She reflected triangle $KLM$ through point $S$ to get triangle $K'L'M'$. Then, by finding the intersections of the corresponding sides of triangles $KLM$ and $K'L'M'$, she obtained the endpoints of the line segment $AB$, which is the desired chord that satisfies the conditions of the task (see the picture).