Answer:
794.19 feet.
Explanation:
Please find the attachment.
Let x be the distance helicopter needs to fly to be directly over the tower.
We have been given that a helicopter flying 3590 feet above ground spots the top of a 150-foot y'all cell phone tower at an angle of depression of 77°.
We can see from our attachment that helicopter, tower and angle of depression forms a right triangle.
As height of tower is 150 feet, so the vertical distance between helicopter and tower will be
feet.
We cab see from our attachment that the side with length 3590-150 feet is opposite and side x is adjacent side to 77 degree angle.
Since we know that tangent relates the opposite side of a right triangle to its adjacent side, so we will use tangent to find the length of x.
![\text{Tan}=\frac{\text{Opposite}}{\text{Adjacent}}](https://img.qammunity.org/2020/formulas/mathematics/high-school/g65isv6n5vex0yp58r3cn67htkwzd1vkex.png)
Upon substituting our given values in above formula we will get,
![\text{Tan}(77^o)=(3590-150)/(x)](https://img.qammunity.org/2020/formulas/mathematics/high-school/lu4p8f8qnywg2aujoj1ym4hqag3to5za8z.png)
![\text{Tan}(77^o)=(3440)/(x)](https://img.qammunity.org/2020/formulas/mathematics/high-school/5pi3hrjzb0u5dmq47g5s55rnv6fdb30gjw.png)
![x=\frac{3440}{\text{Tan}(77^o)}](https://img.qammunity.org/2020/formulas/mathematics/high-school/2gqawdcaf5f6incer31it7hl99q1gfjsrq.png)
![x=794.1865\approx 794.19](https://img.qammunity.org/2020/formulas/mathematics/high-school/2nuggb71t8wr2r4h17rh2hfl6ns1uakxuz.png)
Therefore, the helicopter must fly approximately 794.19 feet to be directly over the tower.