mgh = 1/2mv2
so mv2/L = 2mghL
this is the force normal to string
and at angle theta, net force tangential to string = mgsinθ
so net accn= 2ghL _|_ to string , gsinθ along the string . let angle made by net accn with string = φ
so tanφ =gsinθ2ghL = Lsinθ2h