In a n-sided regular polygon, the probability that the two diagonal chosen at random will intersect inside the polygon is

Three vertices are chosen at random from the vertices of a regular hexagon then The probability that the triangle has exactly two sides common with the side of the hexagon is

In a convex polygon of 6 sides two diagonals are selected at random. The probability that they interesect at an interior point of the polygon is

Two alternate sides of a regular polygon, when produced, meet at right angle. Calculate the number of sides in the polygon.

Three vertices are chosen randomly from the seven vertices of a regular 7 -sided polygon. The probability that they form the vertices of an isosceles triangle is

In a polygon the number of diagonals 77. Find the number of sides of the polygon.

Two alternate sides of a regular polygon, when produced, meet at right angle. Find: the value of each exterior angle of the polygon.

The number of triangles that can be formed using the vertices of a 20 sided regular polygon such that the triangle and the polygon does not have any side common is

If 4 squares are chosen at random on a chess board, the probability that they lie on a diagonal line is

Each side of a regular polygon is 2.5 cm in length. The perimeter of the polygon is 12.5 cm. How many sides does the polygon have?

The number of triangles that can be formed form a regular polygon of 2n + 1 sides such that the centre of the polygon lies inside the triangle is