Texas Instruments: The Orthocenter of a Triangle

In this activity, students learn about the sum of the angles in a triangle. They understand triangles and their interior angles.

Students study the Simson line and analyze the relationship it shares with its triangle. [Requires Adobe Reader.]

Navigator Activity: This is a review of the right triangle in the coordinate plane. Given two lines (2 really nice ones) the students write the equation of the 3rd line to create a right triangle. They find the vertices of the triangle...

In this activity, students investigate the midsegments of a triangle as in the previous activity. They continue to explore these segments and extend their understanding of the relationships that exist between the slopes of lines...

In this activity, students analyze the location of the centroid and orthocenter for different triangles.

In this activity students explore the tangent ratio. Students construct a right triangle using perpendicular lines, and a line that forms the hypotenuse of the triangle. When students construct the hypotenuse line it is very important...

Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...

Young mathematicians explore the concept of triangles as they construct altitudes of triangles to find the orthocenter. Learners construct their triangles using Cabri Jr. on their graphing calculators and find that the altitudes of a...

The centroid, circumcenter, orthocenter, and incenter are the four classic centers of a triangle that are studied in geometry. In this activity, you will construct these center points and discover their properties. [Requires Adobe Reader.]

Students can use the TI-84 Plus family with Cabri Jr. to prove triangle congruence with SSA.