Re: Rounding Edges with Tangents, Worksheets 69-1 and 69-2
If I am understanding your first question correctly, you need to draw the parallel lines so you know where toe begin and end the arc. After you draw the arc, you can erase the 'extra' lines.
With your second question, I pretty much just use whatever equipment I need - even when it is not listed in the 'Materials' section. In fact, I didn't even notice that it was not in the 'Materials' section until you said so. :-) I suppose I should read a little more closely! Either way, Dr. Cotter want the students to figure out the problem and use whatever tools are necessary to get the answer. The way you accomplish the answer might be different from someone else. That is the beauty of this program! It makes the student figure it out and 'think outside the box'.
I hope that has addressed your questions. If not, you can email me at email@example.com or at firstname.lastname@example.org.