QUADRILATERALS | PROPERTIES OF A RECTANGLE; RHOMBUS AND SQUARE, IMPORTANT PROPERTIES ABOUT TRIANGLES | If the diagonals of a parallelogram are perpendicular, then it is a rhombus., If the diagonals of a parallelogram are equal and intersect at right angle, then parallelogram is a square., Each of the four sides of a rhombus is of the same length., The diagonals of a rectangle are of same length, The diagonals of a rhombus are perpendicular to each other., The diagonals of a square are equal and perpendicular to each other., The line segment joining the mid-points of any two sides of a triangle is parallel to the third side of a triangle., The line drawn through the mid-point of one side of a triangle is parallel to another side and intersects the third side at its mid-point.