**HP Prime Geometry App Tutorial Part 2: Triangles**

Like Part 1, we’ll use a Plot window of XRange = [ -16, 16
], YRange = [ -11, 10.9 ], ticks are at 1.
For this lesson, we are going to focus on triangles. Start with a clear Plot Screen ([Shift], [
Esc ] (Clear)).

**Drawing a Triangle**

1. On the plot
screen, press the soft key (Cmds), then select 4 for Polygon and 1 for Triangle.

2. Select the first vertex
(corner point) and press [ Enter ]. For
this lesson, put the triangle wherever you want.

3. Place the second
and third vertex. Press [ Enter ] after
each point. The vertices are labeled A,
B, and C.

**Finding an Angle**

The steps will demonstrate how to find the angle. Be aware that the direction you enter the
vertexes will determine the sign of the angle.

1. Press (Cmds), 9
for Measure, 6 for Angle.

2. Select one vertex,
press [Enter]. Follow the triangle to
select the second vertex (where the angle will be measured), press [ Enter
]. Follow that with a third vertex and
press [Enter]. The angle displayed on
top of the screen.

**Resizing the Triangle**

Click on one of the points of the points. Then drag the point with the arrow pad. When satisfied, press [ Enter ].

For the last part, clear the screen.

**Reflect a Triangle – reflect about a point**

1. Clear the screen. ([ Shift ] [ Esc ] (Clear))

2. Draw a triangle
with the vertices (-6, -4), (-6, 4), and (-12, 0).

3. Press (Cmds), 7
for Transform, 2 for Reflection.

4. You will be promoted
for a reflection point. For this exercise,
set the point at (0,0).

5. Select the
triangle (scroll until the triangle turns red) and press [ Enter ].

In Part 3, we’re going to work with lines and line
segments. Until next time, have a great
day!

Eddie

This blog is property of Edward Shore. 2015.

I don't know for you but for me, after I do a CLEAR, later on when doing a measure, angle are always express in radians, even if I'm set in degree. In fact, I am set in degree everywhere anyway... Whne I see it shows the angle in radian, I press [Shift][Symb](setup) and I see I am in degree. I don't even click on it, I have just to go there to view it. Then I press "Plot" to come back to grid screen and then, by magic, the angle is now shown in degree. Is that normal? Am I missing something?

ReplyDeletePossibly, I'm not sure. I have not noticed this problem.

ReplyDelete