Show that the points A(5, 6), B (1, 5), C(2, 1) and D(6, 2) are the vertices of a square.
Vertices of a quadrilateral are A(5,6), B(1,5), C(2,1) and D(6,2).
Using distance formula =
AB = 
= 
= 
units
BC = 
= 
= 
units
CD = 
= 
= 
units
DA = 
= 
= 
units
AB = BC = CD = DA
BD = 
= 
= 
units
AC = 
= 
= 
units
All the four sides of the quadrilateral are equal and diagonals are of equal length. Therefore, the given vertices form a square.
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