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

Ateam of researchers calculates that a glacier will melt completely away in the next 100 years. which land structure will most likely be left behind after the glacier melts?

Which of the following is a way that advancements in technology improve humans' ability to measure air quality and protect human health?

Find the equation of the line passing through the point (–1, 5) and perpendicular to the line 3x + y = 4.