Remembering that the Native American lands in 1819 comprised 66% of the total square miles of the modern contiguous US (3 million square miles), what percentage of the total square miles of the 2015 Native American reservations are in the contiguous US today?

are their options?

otherwise i can't

radioactive dating, also known as  radioisotope dating  is a process that in  estimating the approximate  age  of  rocks. these data can be analyzed from  the studies dealing with the  decay of the radioactive elements that are present in these rocks. in nature, there are a few types of materials or atoms which are quite unstable and they spontaneously decay or breakdown to form other kinds of atoms.