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.