The estimated age of the Milky Way Galaxy is 13.2 billion years.

Explanation:
The age of the Milky Way Galaxy refers to the length of time since it first formed. Scientists have used various methods to estimate the age of our galaxy, including studying the ages of its oldest stars and analyzing the rates of star formation.

1. Studying the ages of the oldest stars:
By examining the ages of the oldest stars in the Milky Way, astronomers can estimate the minimum age of the galaxy. These stars are known as globular clusters, which are dense groups of stars that formed early in the galaxy's history. Scientists can determine the ages of these stars by measuring their brightness and color. The oldest globular clusters in the Milky Way are estimated to be around 13.2 billion years old.

2. Analyzing the rates of star formation:
Another method used to estimate the age of the Milky Way involves studying the rates of star formation. By observing the current rate at which new stars are being formed, scientists can estimate how long it would take for all the stars in the galaxy to have formed. Based on these calculations, the Milky Way is thought to have taken around 13.2 billion years to form.

3. Combining different lines of evidence:
In addition to studying the ages of the oldest stars and the rates of star formation, scientists have also used other lines of evidence to estimate the age of the Milky Way. This includes studying the chemical composition of the galaxy, the distribution of its stars, and the presence of elements that are created in stellar explosions.

In conclusion, based on the analysis of the ages of the oldest stars, the rates of star formation, and other lines of evidence, scientists have estimated that the age of the Milky Way Galaxy is approximately 13.2 billion years.