Final answer:
The sine of the angle between the ground and the line that connects the tip of the shadow to the top of the tree is approximately 0.7059.
Step-by-step explanation:
To find the sine of the angle between the ground and the line that connects the tip of the shadow to the top of the tree, we can use the properties of similar triangles. Let's label the height of the tree as 'a' and the length of the shadow as 'b'. We have a right triangle with the height as the opposite side and the shadow as the adjacent side. The sine of the angle can be found using the formula sine(angle) = opposite/hypotenuse, which in this case is a/b. So, the sine of the angle is a/b = 60/85 = 0.7059 (rounded to four decimal places).