Answer: 4545 yards
Explanation:
We can use similar triangles to solve this problem. Let's represent the height of the flagpole with the variable "x".
Using the triangle formed by Carla's line of sight, the height of the apartment building, and the top of the flagpole, we can set up the following proportion:
x / (x + 1515) = 15 / 20
Simplifying this proportion, we get:
4x = 3(x + 1515)
4x = 3x + 4545
x = 4545
Therefore, the height of the flagpole is 4545 yards.