If Darius stands on a hilltop and watches Saskia, who is walking in a valley with a tall tower between them, will Darius be able to see Saskia as she walks on a straight path on the other side of the tower from his perspective?

Provide a very brief response.
Darius will not be able to see Saskia as she walks on the path on the other side of the tower from his perspective. The tower will obstruct his view of Saskia because it is a tall structure placed directly between his line of sight and her path. Even though Darius is on a hilltop, if the tower's height surpasses the elevation of the hill and Saskia remains at ground level in the valley, the tower will block Darius's view of her until she emerges from the other side of the tower along her path.