## Saturday, August 29, 2015

### Rhombus and Cyclic Quadrilaterals Properties and Proof Video

In this video I have explained first about the properties of Rhombus and how to find out its area. I have also told what is the basic difference between Parallelogram and Rhombus. If all the sides of a Parallelogram becomes equal then a Rhombus if formed. The diagonals of a Rhombus intersect each other perpendicularly, its proof has also been done.

After that I have taken up cyclic quadrilaterals and have explained some very important properties of cyclic quadrilaterals. Two formulae relating to cyclic quadrilaterals have been discussed by me in the video. They are -

1. Area = ((s-a)(s-b)(s-c)(s-d))1/2

Where s is the semiperimeter and a,b,c,d are the length of the sides of the cyclic quadrilateral.

2. The Product of Diagonals of a cyclic quadrilateral  = Sum of the product of length of opposite sides of a cyclic quadrilateral.

These two are very important formulas when it comes to solving questions and you can also find questions involving the direct usage of these two formulas. So you are requested to repeatedly watch the video to understand it. At the end I was to discuss some questions related to quadrilaterals but could not do it so I would finish with those questions after finishing the theory part of circle. Next video will be on circles.

Doubts and comments are most welcome.

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