Geometry Explorer Help
Using the Measure Menu:
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The items in the measure menu deal with measuring various geometric
properties. These include:
x-Coordinate: Selection- point. Measures the x-coordinate of
the point in the Euclidean coordinate system. (Euclidean canvas only)
y-Coordinate: Selection- point. Measures the y-coordinate
of
the point in the Euclidean coordinate system. (Euclidean canvas only)
Distance: Selection - 2 points or a point and a linear
object
(line,
ray, segment). Measures the distance between the points (or the point
and linear object).
Angle: Selection - 3 points (initial, vertex, terminal)
Measures
the oriented angle from the initial point to the vertex to the terminal
point.
Defect: Selection -3 points. Measures the defect in a
hyperbolic
triangle. (Hyperbolic Geometry only)
Excess:Selection -3
points. Measures the excess in an elliptic triangle. (Elliptic Geometry
Only)
Slope: Selection - linear object (line,ray,segment).
Measures the
slope of the linear object. (Euclidean canvas only)
Length: Selection -segment. Measures the length of the
segment.
Ratio: Selection - 3 points, 4points, or 2 segments.
Measures
the ratio of two lengths. These two lengths can be defined three ways:
2 segments, two sets of endpoints (4 points), or three points (lengths
are first-second and second-third).
Radius: Selection -circle or arc. Measures the radius of
the
circle
or arc.
Circumference: Selection -circle. Measures the
circumference
of
the circle.
ArcAngle: Selection - arc. Measures the angle defined by
an
arc
and the center of the circle it lies on.
ArcLength: Selection - arc. Measure the length of an arc.
Perimeter: Selection - a filled polygon. Measures
the
perimeter
of the polygon.
Area: Selection - a filled polygon, circle, or arc.
Measures
the
area of the object.
Measurements are done by first selecting the objects that define the
measurement and then choosing the appropriate measurement from the
Measure
menu.
Look here for an interesting
example
that uses measurements extensively. (Level of example is advanced).
Table
Options:
Create
Table: Use this option to create a table to record measurement
values from currently selected measurements. Look here for an example of using a table to explore
the angles of a quadrilateral.
Add to
Table: Use this option to add new columns of measurement values.
Edit
Table: Use this option to edit the names of the measurements in
the table.
Other options:
Input
Parameter: Choose this option if you want to insert an
input box in the canvas. Numerical values may be typed
directly into the input box and used just like other numerical
measurements.
Slider:
Choose this option to create a slider on the screen. The slider works
as a numerical measurement that changes in value as the slider knob is
moved.
Duplicate
Measure: Choose this option to make a copy of any measurement in
the canvas.