



 
Hi Jose, I would first construct a quick sketch to make sure it looks like a rhombus.
It does look like a rhombus so now I have to decide how I will show that the four sides have equal lengths. I could use the distance formula (which is just Pythagoras' Theorem in an algebraic form) but I would rather use Pythagoras' Theorem directly to find the length of each side. For example to find the length of AB add a point P(2,2) which forms a right triangle APB.
The length of AP is 1 + 2 = 3 and the length of PB is 6  2 = 4 and hence from Pythagoras' Theorem the length of BA is
Now find the lengths of the remaining 3 sides. Penny  


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