Create
a new point, then right click on it to open the "Edit
Point" dialog. Check the "Fixed" box, then click
"OK". Try to move the point by dragging with the right mouse button.
The point will not move.
Duplicate
the first (upper) object at left in the empty area of the
construction
window. Use only two segments in your construction, like a "T"
. Create the top of the "T" first; then place one endpoint of
the second segment on the first segment (make sure the segment
highlights before you click to create the point).
Try
moving the point of intersection of the two segments (drag
with right mouse button). The point remains on the first segment.
Right
click (do not drag) on the point of intersection, to open up the
Properties dialog. Click "Release Point," then move the point
again. Now the point can jump off the segment.
Now
duplicate the lower object at left. First create two crossing
segments. Then creat a third segement with one endpoint at
the intersection of the first two.
As you move the endpoints of the two crossing segments, the point of
intersection moves, and so does the third segment. If you move an
endpoint so that the segments no longer cross, then the third segment
disappears entirely: it is no longer valid.
It's
possible to move multiple points together using the "Move" tool as
follows:
- First select the "Move" tool.
- Then hold down the "shift" button and click on
several points in the window. If the point is
moveable, it will be highlighted in red (for instance, that the
intersection of the three segments is not moveable).
- Finally, release the "shift" and place the mouse over
one of the highlighted points so that the cursor becomes a hand. Left
click and drag to move the selected points.
Try
again to move multiple points as in the previous paragraph, only this
time when you release the "shift" hold down the "ctrl" button
while you drag the points.You will see that the original state of the
construction remains visible as you move the points. When you let go of
the mouse, the original state disappears, and is replaced by the new
construction.
Notes:
- Typing "m" selects the "Move" tool.
- When the "Move" tool is first selected, all
movable objects are highlighted. The "Move" tool has no effect on
objects that are not moveable (for instance, points of intersection
between crossing segments).
Continue
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