This document provides instructions for finding the orthocenter of a triangle using a TI-Nspire calculator. It outlines the keystrokes to create a geometry window, construct a triangle by defining three points, and then construct the altitudes of the triangle by drawing lines from each vertex perpendicular to the opposite side. The orthocenter is the point where all three altitudes intersect.

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TI-Nspire Mini-Tutorials
Finding the Orthocenter of a Triangle
Summary of Keystrokes
Create a geometry window:
c13
Construct the triangle:
b91
(Use ¤¢`¡ to move to the middle of the screen. Press · to
define the first point of the triangle. Repeat with the other two points.)
Construct the altitudes of the triangle sides:
bA1 ¤¢`¡ (Use to move to each of the
·
triangle’s sides. Press then move the pointer to the opposite point
·
and press . Manipulate the triangle by moving to one of the points,
a {
holding , until you see and then moving the point.)