Show that the bisectors of angles of a parallelogram form a rectangle.

Show that the diagonals of a parallelogram divide it into four triangles of equal area.

Show that the angle bisectors of a triangle are concurrent.

Find the measure of all the angles of a parallelogram, if one angle is 24^(@) less than the twice of the smallest angle.

Show that the points A(1,2,3),B(-1,-2,-1),C(2,3,2) and D(4,7,6) are the vertices of a parallelogram ABCD, but it is not a rectangle.

Using vector method, prove that if the diagonals of a parallelogram are equal, then it is a rectangle.

State whether the statements are True or False. (vi) All parallelograms are rectangles

Are a rectangle and a parallelogram similar. Discuss.

If AD is the bisector of angle A then AC is

Construct the bisector of a given angle ABC.