Why do astronomers know that you live in a spiral galaxy if we are inside it?

Astronomers know we live in a spiral galaxy, specifically the Milky Way, by observing its structure and dynamics from various vantage points. They use techniques like mapping the distribution of stars, gas, and dust, as well as analyzing the rotation curves of the galaxy. Additionally, observations of the galaxy's shape and features, such as spiral arms and a central bulge, provide clear evidence of its spiral nature. Despite being inside it, we can infer its structure through these observations and comparisons with other galaxies.