The above figure shows and intersecting at
E. List *all* the statements about the
angles in this diagram that you think are true (see #1 for an example). Use the
notation to denote Òthe
measure of angle DEAÓ. Assume all measures are relative arcs.

1)

Go to http://tpc2.net/math34/. Click on the *Test your hypotheses* link.
Use the GSP sketch to test your hypotheses or to make even more hypotheses.
(Note that GSP gives angle measures in degrees.)

On the back of this sheet, list the hypotheses that seem to
be true. Pick one of these hypotheses. Provide an argument for why it *must* be true.

These hypotheses seem to be true:

Here is an argument that hypothesis #___ is true.