Geometry App - HP Prime Graphing Calculator Quick Start Manual

Geometry app

The Geometry app enables you to draw and explore geometric constructions. A
geometric construction can be composed of any number of geometric objects, such as
points, lines, polygons, curves, tangents, and so on. You can take measurements (such
as areas and distances), manipulate objects, and note how measurements change. To
open the Geometry app, press ! and select Geometry. The app opens in Plot view.
Plot view In Plot view you can directly draw objects on the screen using the
Commands menu (tap
and then select Circle. Now, tap where you want the center of the circle to be and
press E. Next, tap a point that is to be on the circumference and press E. A
circle is drawn with a center at the location of your first tap, and with a radius equal to the distance between your first and
second tap.
Note that there are on-screen instructions at the bottom of the display to help you. For example, Select another
point means tap the location where you want the point on your circle to be. The current command and the pointer
coordinates are also displayed at the bottom of the screen. Always confirm your intention by pressing E after tapping
the screen, and press & when you have finished drawing an object. This deactivates the drawing tool.
Each geometric object you create is given a name. This includes the points that make up a multi-point object. Thus if you
create a polygon, the polygon is given a name, and so too is each point at each vertex and each segment. If you create a circle,
the circle is given a name (C in the example above). So too is the center point (A) and the point on the circumference (B).
To select a point in Plot view, just tap it. If the object you tap is a point and there are multiple points available, a window listing
of all the points appears. Select the one you want, and then press E. If the bottom right of the screen shows the name
of the object, you have accurately selected it; otherwise a list of nearby objects is shown, indicating that the object has not
been selected.
If no object is selected, you can pan by dragging a finger across the screen: either up, down, left, or right. You can also use
the cursor keys to pan provided that the cursor is at the edge of the display. You can zoom by pinching, by pressing + or
:, or by tapping and choosing a zoom option from the zoom menu. The options are the same as you find in the
Plot view of many apps: Zoom In, Zoom Out, Zoom Undo, Zoom Box, Autoscale, Zoom Integer, and Zoom Decimal.
The categories in the Commands menu are as follows:
• Zoom—Contains zoom options, such as zooming in or out and so on.
• Point—Contains point options, such as point and midpoint and so on. For example, to add a point on a segment
equidistant from its two ends, select the segment, tap
• Line—Contains straight objects, such as a segment, ray, line, tangent, and so on.
For example, to add a tangent to a circle:
1. Tap , tap Point, select Point On, and then tap the circle where you want
the point of tangency to be.
2. Now, tap , tap Line, and then select Tangent.
3. Tap the circle, press E, tap the point of tangency, and press E. A
tangent is drawn to the circle through the point of tangency. Note that the point
and the tangent are given names (D and E respectively in the example on the
previous page).
• Polygon—Contains polygon options, such as a triangle, quadrilateral, and so on.
• Curve—Contains options for curved objects, such as a circles and conic sections, as well as the menu option Locus.
Quick Start Guide
). For example, to draw a circle, tap , tap Curve,
, tap Point, select Midpoint, and then press E.
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