# What is the circumference of the Milky Way?

Mar 22, 2018

The perimeter of an ellipse is to an approximation given by:

$2 \cdot \pi \sqrt{\frac{{a}^{2} + {b}^{2}}{2}}$ wher $a$ and $b$ are half the minor and major axis. .. See below.

#### Explanation:

The Milky Way is considered to be an ellipitcal galaxy with an estimated minor axis of 100,000 light years and a major axis of 175,000 light years.

The perimeter of an ellipse is to an approximation given by:

$2 \cdot \pi \sqrt{\frac{{a}^{2} + {b}^{2}}{2}}$ wher $a$ and $b$ are half the minor and major axis.

PLug in the values and work it out.