


Let ABCD is rhombus where AC and BD are the diagonals.
Let length of diagonals AC and BD are given.
Now, from the triangle BOC,
Apply Pythagoras Theorem,
(BC)2 = (CO)2 + (BO)2
=> (BC)2 = (AC/2)2 + (BD/2)2
=> BC = √{(AC/2)2 + (BD/2)2 }
In this way, we find the length of the side of the rhombus.
