Which is a unit rate?
Pls help

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.

Describe the relationship between the angles of similar triangles and the sides of similar triangles

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°