Answer:
289.877 ft
Explanation:
You can draw the eagle and mouse by using a right triangle. You know that the height of the triangle will be 280 feet and the distance between eagle and mouse should be the hypotenuse. Since we know the angle and one side of the triangle, we can use trignometry (cosine(angle)=adjacent/hypotenuse). Plug in your values and solve for the hypotenuse.