Geometry

 

Let X be a point inside rectangle ABCD.  If AX = 3, BX = 3, and CX = 3, then find DX.   

 

                                        AX² + CX²  =  BX² + DX²         

 

                                         3²  +  3²  =  3²  +  DX²     

 

                                         DX²  =  3²  

 

                                          DX  =  3    

 

 

i copied the following from the internet.  

In Euclidean geometry, the British Flag Theorem says that if a point P is chosen inside a rectangle ABCD, then the sum of the squares of the Euclidean distances from P to two opposite corners of the rectangle equals the sum to the other two opposite corners. 
_.