HP Prime Geometry App Tutorial Part 1: Circles

This tutorial series will focus on the HP Prime’s Geometry
App. Most of the time we will focus on
the Plot screen. The software version
that we are working with is Build 8151 (6/17/2015).

**Setting Up the Plot Screen**

For the tutorial, I am going to set the plot screen with the
following parameters: XRange = [-16, 16],
YRange = [-11, 10.9], and the ticks for both axes are 1.

Steps:

1. Press [ Shift ], [
Plot ] (Plot Setup).

2. Set up the parameters
as shown below. Note that the Xmax and
Ymax are automatically set. I also
recommend that you set the calculator to Degrees mode through the Settings
Menu.

For this lesson, we are going to draw a circle, draw its
radius, find its circumference, and its area.

**Draw a Circle**

1. Press [ Plot ] to go the plot screen. If necessary, clear the workspace by pressing
[ Shift ], [ Esc ] (Clear).

2. Press the soft
menu key (Cmds), select 5 for Curve, 1 for Circle. You are prompted to determine where the
center of the circle.

3. For this lesson, just move the cursor, or click on/touch
the screen anywhere you like. Press [
Enter ] to anchor the circle’s center.

4. Select a point to
determine who far the circle expands.
Pressing [ Enter ] will draw the circle, and plot the point you selected
on the circle’s edge.

Note how everything is labeled. A is the center, B is the outer point, and C
is the circle. If you were to refer to
these objects outside of the plot screen (like the Num screen or the CAS Home
screen), you will need to have a G (capital “G”) suffix attached, like this:
GA, GB, GC.

**Draw the Radius of a Circle**

1. Go to the center
of the circle (point A). You can scroll
your cursor by using the arrow keys or touch on/click on the screen. As of the current version (8151), there is no
“Go To” feature (hopefully on a future update).

2. Press (Cmds), 3
for Line, 1 for Segment. Select the
center by pressing [ Enter ].

3. Select any of the circle’s
edge and press [ Enter ]. The radius,
represented by the line segment is drawn.

**Measuring the Circle’s Radius (the easy way)**

1. Press (Cmds), 9
for Measurement, 2 for Radius.

2. Select the
circle. When the circle is selected when
it turns red. Press [ Enter ].

3. The result will be
on top of the Plot screen.

**Measuring the Circle’s Area**

1. Press (Cmds), 9
for Measurement, 5 for Area.

2. Like the last
exercise, select the circle. Again, you
know if the circle is selected (by the cursor’s placement) if the circle is
red. Press [ Enter ].

3. The circle will
filled with color and the result will be on top of the Plot screen.

That is going to wrap up Part 1 of the HP Prime Geometry App
Tutorial. In Part 2, we’ll be working with
Triangles, finding angles, re-sizing, and reflecting triangles. Until then, have a great day!

Eddie

This blog is property of Edward Shore. 2015.