>> This is a short video giving you some hints on Number 9.
For Problem 1 of Part A, we are given the front and top views,
and we're asked to sketch the opposite section
for each of the solids.
So, for the first one, here is the top view,
and here's the front view.
I didn't complete the front view.
Here's the top and here's the front.
And we want to clarify the hidden lines here.
So we need to do an offset section,
so an offset section is one.
I've got one that is a cutting plane
that doesn't go all the way through; but, instead,
the position is offset in order to go
through the main features of the solid.
So here, this is the location of our offset section here cutting
in this direction and then offset so that it goes
through the center of this tiny little circle.
And these arrows indicate the direction of the line of sight.
So, in that case, when we create the corresponding offset section
in the front, so we're going to --
we're going to make this a solid line here.
And the two hidden lines here will become solid also,
corresponding to the cylindrical holes.
One here. And then we just need to section
by adding the hatch line section lines.
This area here will be sectioned, sectioned.
This area here will also be sectioned.
This area here is not sectioned
because the cutting plane doesn't go
through the solid part here.
Similarly, no section here for the holes.
Now, for the second part, Part B of Problem 1 of Part A,
we're given the front and top views again.
This time we want -- it's asking us to sketch half section
because the objects here are -- have symmetry.
So we don't need to do a full section.
So that means, if I choose to do the cutting section
on the left side, my cutting section will only go from here
to here, and my line of sight's going this way.
So my half section would look something --
the hidden line here becomes a solid.
The hidden line from the hole becomes a solid.
And then we're going to have a solid line here.
And this is, of course, the position
of our [audible] line here.
I did not keep any of the hidden lines on the right side.
That's not sectioned.
So all I have to do is just add section lines here,
section lines here.
And then add the centerline, of course, for the circle here
and for the centerline here.
And on the right side you don't show any of the hidden lines.
Now, for Part B of Lab 9,
we are given originally the top and the front.
And the first part of it is asking us
to convert the given front view into this offset section AA.
So here's the location of our offset section.
And, if we do a cutting section here along AA
and show the different views, you don't need
to construct a separate front view.
You just turn the front view into the opposite section.
So this will be hatched here, hatch, hatch, hatch.
And for the last part of Problem B,
we're asked to find section BB and show that here to the right.
In section BB we're supposed to do a phantom section.
And note this here.
This is a phantom section.
We leave all the hidden lines the way they are.
So, in this case, first construct the right side view,
a regular right side view.
And then do not change any of the hidden lines,
and simply hatch the arrows that correspond to solid portions cut
by your cutting plane BB.
So it's going to look like this.
And take note that you need to use the correct hatch pattern
for the given material.