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

Prove that the bisectors of two opposite angles of a parallelogram are parallel to each other.

Prove that the bisectors of two adjacent angles of a parallelogram are perpendicular to each other.

Area of a parallelogram =_____

Prove that a cyclic parallelogram is a rectangle.

overset(harr)("AB ") and overset(harr)("DC ") are two parallel lines and a transversal l, intersects overset(harr)("AB ") at P and overset(harr)("DC ") at R. Prove that the bisectors of the interior angles form a rectangle.

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

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

Show that the angles of an triangle are 60^(@) each.

A parallelogram is formed by the lines ax^2 + 2hxy + by^2 = 0 and the lines through (p, q) parallel to them. Show that the equation of the diagonal of the parallelogram which doesn't pass through origin is (lamdax-p)(ap + hq) + (µy - q) (hp + bq) = 0 then µ^3+λ^3 is