Explanation

Given:

1. The horizontal distance from Ali to the base of the tree = 10 m.
2. The vertical distance from Ali’s eyes to his feet = 1.5 m.
3. The hypotenuse from Ali’s eyes to the top of the tree = 15 m.

Step-by-step solution:

1. Let the height of the tree be $h$. Since Ali’s eyes are 1.5 m above the ground, the height of the tree above Ali’s eyes is $h - 1.5$.

2. Using the Pythagorean theorem in the triangle formed:

   $$$$10^2+(h−1.5)^2=152

3. Simplify:

   $$$$100+(h−1.5)^2=225

4. Subtract 100 from both sides:

   $$$$(h−1.5)^2=125

5. Take the square root of both sides:

   $$h - 1.5 = sqrt{125}$$ $$h-1.5\approx 11.18$$

6. Add 1.5 to both sides to get $h$:

   $$$$h=11.18+1.5=12.68 m