Here's a breakdown:

* Pollux is a giant star, classified as a K-type orange giant.

* Sun's diameter: 1.39 million kilometers (865,000 miles)

* Pollux's diameter: 16.6 million kilometers (10.3 million miles)

This means Pollux is significantly larger than our Sun, but it's important to note that its diameter is still relatively small compared to other giant stars in the universe.