To start our next lesson, let's copy down the standard. [b]LT5.4 - I can use properties of altitudes and orthocenters in triangles.[/b] Let's write these definitions in the vocabulary section on the last page of our packet: [b]Altitude -[/b] Segment from a vertex of a triangle that is perpendicular to the opposite side. [b]Orthocenter -[/b] Point of concurrency (where the lines all interest together) of the three altitudes of a triangle. Let's use the applet below to explore how altitudes are created.

Now that you have explored with Altitudes and Orthocenters, practice your new learning to check your understanding. [b]Practice: pg 340-342 #16-20, 24, 25, 34, 35 [/b]