DOI: 10.36347/sjpms.2020.v07i04.001

Pages: 40-45

In this paper we discuss a kind of symmetric configuration for planar concave 5-body problem with four of the five bodies on the vertex of an isosceles trapezoid and the other on the axis of symmetry inside the isosceles trapezoid. Then we give a special case to prove that there exist a set of positive masses to make this configuration a central configuration when the inner body not coincident with the center of mass.