The Andromeda and the sea monster story is quite an interesting one. Andromeda was offered as a sacrifice to appease the sea monster that was terrorizing the kingdom. She was tied to a rock by the seashore, waiting for the inevitable. Meanwhile, Perseus, after his great adventure of beheading Medusa, was flying around. He noticed Andromeda's plight. He knew he had the means to save her with Medusa's head. When the sea monster emerged, Perseus showed the head and the monster was turned to stone. This not only saved Andromeda but also led to a new chapter in her life as she became Perseus' wife, and their story became part of the rich tapestry of Greek mythology.
In the Andromeda and the sea monster story, Andromeda was chained to a rock as a sacrifice to a sea monster. Perseus, a hero, saw her and was smitten. He used the head of Medusa to turn the sea monster into stone and then rescued Andromeda. They often end up getting married in the story.
Well, the story goes like this. Andromeda was the daughter of a king and queen. An oracle told them to sacrifice Andromeda to the sea monster to stop its rampage. So she was chained up. Perseus happened to fly by on his winged sandals. He was on his way back from slaying Medusa. When he saw Andromeda in distress, he decided to help. Using the power of Medusa's head which could turn things to stone, he faced the sea monster and saved Andromeda. It's a classic tale of heroism and rescue, and their union later was also a significant part of the story.