Answer: SP=5 cm
Explanation:
Since, Here PQRS is a kite where PR and SQ are the diagonals of the kite.
Let, PR is the major diagonal of the kite PQRS.
And let T is the intersection point of the diagonals.
Thus by the property of the kite diagonal PR bisect SQ with right angle.
⇒

Therefore,

⇒
=
( we can not take the negative value of root)
But, PQ=SP
Therefore, SP= 5 cm
Note: If we take SQ as the major diagonal then we also get the same result.