 In today's videos, we are going to focus on rhombi and squares. So we're going to start off here talking about properties of a rhombus. And a rhombus has all of the same properties as a parallelogram plus three additional properties. So we're going to start here writing a rhombus is a quadrilateral that has all properties of a parallelogram and all four sides are congruent. The next property of a rhombus has to do with the diagonals. The diagonals of a rhombus are perpendicular. And remember the symbol for perpendicular is an upside down T. That also means if I look up here at the picture that I would be able to show that angle B is a right angle because we know perpendicular means two segments that form 90 degree angles. And then the last property has to do again with the diagonals. But this time talking about the diagonals bisect a pair of opposite angles. Sorry for my poor penmanship here. So opposite angles get bisected by the diagonals. Which means that for example angle O has now been broken into two congruent angles by that diagonal.