Question 814923
What remained was 4 
distance from ground = 5
they form a right triangle

Apply Pythagoras theorem

One leg				4	m
Second leg				5	m
Hypotenuse				x	m
By Pythagoras theorem					
Hypotenuse^2 = Leg1^2+leg2^2					
{{{	x 	^2	=	4^2+5^2}}}
x 	^2	=	16	+	25
x 	^2	=	41		
{{{ sqrt(x^2)=		sqrt(	41	)}}}	
x=	6.4	m	

Height of tree = 6.4 +4 =10.4m