Question 860831
Assuming the tree is vertical at right angles to the ground

then it is a right triangle

The tree,ground and the line from top of tree to the end of shadow.

(x+4)^2=x^2+(x-46)^2

x^2+8x+16=x^2+x^2-92x+2116

x^2-8x-92x-16+2116=0

x^2-100x+2100=0

x^2-70x-30x+2100=0

x(x-70)-30(x-70)=0

(x-70)(x-30)=0

x=30 OR 70
shadow is x-46

so it cannot be 30

so x= 70