 Hello and welcome to the session. In this session we discuss the following question which says explain an isosceles triangle is symmetrical about the bisector of the angle included between the equal sides. First we recall the definition for linear symmetry a figure is said to be symmetrical about a line it is identical either side of the line. This is the key idea that we use for this question. Let's see the solution now. Consider this isosceles triangle PQR with the side PQ equal to the side PR. This angle P is the angle included between the equal sides PQ and PR and we have taken this PS as the bisector of the angle QPR. So we have to show that the triangle PQR is symmetrical about the line PS which is the bisector of the angle QPR. Now if the triangle PQR is folded along the bisector of the angle QPR that is PS then the triangle SQ coincides exactly with the triangle PSR. Thus we can say that the triangle PSQ is identical with the triangle PSR so we say the isosceles triangle PQR is symmetrical about the bisector of the angle QPR which is the angle included between the equal sides of the isosceles triangle. So this completes the session. Hope you have understood the solution of this question.