The point at which all three altitudes of a triangle intersect is called the
a. orthocenter.
b. centroid.
c. base.
d. altitude.

I think it the Centroid 

hope this helps XD

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!