What natural phenomenon on earth provides information on the structure of earth's core?

Shanti wraps the gift she is taking to a friend's birthday party. she doesn't have very much paper, so she does not overlap any of the edges. how much paper did it take to cover the gift?

Which continents lie only in the northern hemisphere

In the figure, polygon abcd is transformed to create polygon a′b′c′d′. this transformation is a by a factor of .