Geometry

 

In quadrilateral PQRS, PQ = QR = RS = SP, PR = 4, and QS = 16.  Find the perimeter of PQRS.    

 

There's a formula for the perimeter of a rhombus in terms of its diagonals.    

 

                              P  =  2 • sqrt(p² + q²)   where p and q are the diagonals      

 

                              P  =  2 • sqrt(16 + 256)  =  2 • sqrt(272)  =  2 • sqrt(16 • 17)       

 

                              P  =  8 • sqrt(17)    

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