Final answer:
Agamemnon sacrifices Iphigeneia to appease the goddess Artemis to allow the Greek fleet to sail to Troy, reflecting on the costs of war and sacrificial customs.
Step-by-step explanation:
Agamemnon kills his daughter Iphigeneia as part of a tragic story from ancient Greek mythology and literature. According to the myth, Agamemnon sacrificed Iphigeneia to appease the goddess Artemis, who had stilled the winds, preventing the Greek fleet from sailing to Troy. This sacrifice was deemed necessary to ensure the success of the Greek forces in the Trojan War. This act is often interpreted as a commentary on the grim realities of sacrificial rituals and the devastating personal costs of war.