The main idea of the passage is "Maya Lin was just a student, but her design won a national competition for the Vietnam Veterans Memorial."
This is a sentence that encloses all the ideas of a text and shows the focus of the author.
The excerpt presented focuses on Maya Lin who was just an architecture student competing with professional architects but still managed to get the prize in a design national competition.
Based on this, the main idea or focus is that despite Maya being a student she won a national design competition.
Learn more about main idea in: https://brainly.com/question/895081