The height of this tree is about 7 meters.

Let B 1N⊥AC 1 be n.

① as shown in figure (2), b1n = an = ab1sin45 = 43× 22 ≈ 5 (m).

NC 1 = nb 1 tan 60 = 26×3≈8.5(m)。

AC 1 = an+NC 1 = 5+8.5 = 13.5(m)。

A: The shadow length is about13.5m when the tree forms an angle of 45 with the ground.

(2) As shown in Figure (2), when the tree forms an angle of 60 with the ground, the shadow length is the maximum AC2 (or the shadow length is the maximum when the tree is perpendicular to the light or when the light is tangent to⊙A with a radius of AB).

AC2=2AB2≈ 14。

A: The maximum shadow length of a tree is about14m.