Jernita Randolph

LetŐs
look at the orthocenter. The
orthocenter of a triangle is the common intersection of the three lines
containing the altitudes. An
altitude is a perpendicular segment from a vertex to the line of the opposite
side. The orthocenter does not
have to be on the segments that are altitudes, but it does lie on the lines
extended along the altitudes.

For acute triangles the orthocenter will be in the interior
of the triangle.

For
obtuse triangles the orthocenter will be outside of the triangle.

For
right triangles the orthocenter will lie on the side of the triangle opposite
the right angle.

Use
the GSP to explore the orthocenter for yourself.