Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Analytic Geometry
• Math: Geometry: Triangles

9-12

45 Minutes

• ##### Device
• TI-Nspire™ Navigator™
• TI-Nspire™
• TI-Nspire™ CAS
• ##### Software

TI-Nspire™
TI-Nspire™ CAS

2.0

## Hey, Ortho! Whats Your Altitude?

#### Activity Overview

In this activity, students will explore the altitudes of a triangle. Students will discover that the altitude can be inside, outside, or a side of the triangle. Students will discover that the altitudes are concurrent. The point of concurrency is the orthocenter. Students should discover the relationship between the type of triangle and the location of the point of concurrency. Students will discover properties of the orthocenter in equilateral triangles.

#### Key Steps

• In this activity, students will explore the altitudes of a triangle. Students will investigate if the altitude is inside, outside, or a side of the triangle based on the type of triangle.

• Students will discover that the three altitudes of a triangle are concurrent. The point of concurrency is the orthocenter.

• Students will also explore the altitude of an equilateral triangle. Students will investigate properties of a point on the inside of the triangle and how it relates to the length of an altitude.