Math 487 Lab 3: Distance from Lines

Sketchpad Lore: Read this first

• In Geometry Through the Circle (GTC), long names are given for files or tools for the Macintosh and short cryptic ones for Windows.  This is no longer necessary in GSP 4.  Use the long Macintosh names.
• GTC was written with directions for GSP3.  One difference is the way tools are handled.  You make the tool the same way, by selecting all or part of a construction and choosing New Tool.  But in GSP4, the New Tool command is in the tool tab (the bottom double arrow item in the toolbox on the left).  When you make a tool, you can check a box to see the Script view.  Check this.  You can use script view to change order of givens, rename objects, write comments, etc.
• In GSP4, the tools are not saved to a separate file, they are saved in the same file as the construction.

Distance from a Point to a Line

1. Work through Exp 5.2, Investigation 2: Construction – Distance Slider

Answer in Writing: Q1, Q3

2. Continue the same Investigation 2: Construction – Other Measurements

Answer in Writing: Q2, Q4 (there may be a typo here: the relationship is between CD and CE), Q6

Strips

3. Work through Exp 5.3, Investigation 1: Within an Inch of a Line. 

Construct in Sketchpad the object for Q2.

Answer in Writing: Q1, Q3

In GSP, modify the experiment as in Explore More – Distance to a Segment. Sketch on the report the outline of the object in this exploration.

4. Create 3 tools, the two tools in Exp 5.3, Investigation 2: Scripts for Strips and one other. [Just read over quickly the section Construction – A Strip and its Midline.]

·        Make the Tool described in Construction – Constructing a Strip from the Midline and a Point.

·        Make the Tool described in Construction – Constructing a Strip from the Midline and a Length.

·        Make a tool Circle by Center + Tangent Line that will take as input a point C and a line AB and construct a circle as in the Figure on page 61 (without the interior).  This tool, used twice, would construct the figure on page 62,

Ripples, Strips, and Inscribed Circles

5. Work through the first 3 pages of Exp 5.3, Investigation 3, Ripples, Strips, and Inscribed Circles.  These investigations are about two intersecting strips.

Answer in writing, Q1, Q2, Q3, Q4

6. Continue with the rest of Exp 5.3, Investigation 3:

• Work through Construction -- Three Strips from a Triangle and the Experiment
• Work through Construction – Intersection of Angle Bisectors and the Incircle and the Experiment
• Work through Construction – More Lines and More Concurrence and the Experiment
• Work through Construction – Exterior Bisectors and Excircles and the Experiment
• Work through Construction –Excircles and the Experiment

Check off on the Report when you have completed these constructions.

Answer in writing, Q1, Q2, Q3.  These are the Major Conclusions from the Lab.