Answer: 48°
Step-by-step explanation:
The shadow is the adjacent side and the length of the flag is the hypotenuse
[tex]cos\ \theta=\dfrac{adjacent}{hypotenuse}\\\\\\cos\ \theta=\dfrac{10}{15}\\\\\\cos^{-1}(cos\ \theta)=cos^{-1}\bigg(\dfrac{10}{15}\bigg)\\\\\\.\qquad \qquad \boxed{\theta=48^o}[/tex]
