If two triangles are similar with a zoom factor of 3, and the smaller one has area 12 sq. units, what is the area of the bigger one? the answer is 108 sq units, im curious how it got there

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.