In this lecture, let us learn about constraints, constraints and the limitations or rules and regulations that we applied to sketching entities. Here in the sketch palette, we can see the constraints, we have a number of constraints like coincident, collinear, concentric, etc. First of all, you can highlight the show constraints, so that the constraints are visible to us. So, first I'm applying the concentric constraint to these two circles. So, the two circles will turn concentric to each other. Now, the horizontal and the vertical constraint I can use so that these two dots are aligned, then I can use the equality constraints to make the circles equal That is the diameter will be equal.

Now, using the symmetric constraint, I can make these two circles symmetric to this line. Now, if I move this line you can see that because it has to maintain this rule, what the circles will be symmetric. Now you can see when I'm dragging this circle is moving here and there it is changing the size also, if I do not know the dimension, but I do not want it to move from its place, I can use the fix or unfixed option. So, I have to select the entity first or select the icon first and then click on the entity. You can see it has turned green now, I wouldn't be able to drag it Next, let us apply again the horizontal constraint. And now the collinear constraint, these two lines will be collinear to each other.

So when I'm dragging, you can see the constraints will remain intact. Now the tangency constraint to this line and the circle. Now using the coincident constraint, I can keep the two intersecting lines together. Now I'm taking the equality constraint for making these lines equal Lindland. Now for these two lines, I can apply the perpendicular constraint. Now you can see there are only a few constraints that are highlighted when I select a particular entity.

So only the possible constraints will be shown for that particular entity which I can also get by right clicking that entity. So, even without going to the sketch palette, just by right clicking, we can obtain the constraints that can be applied to that entity. Now I'm going to create a spline over here, if you see here, so here I have to use the curvature constraint Now if I remove this show constraints, you can see that I will not be able to see the constraints but they still are available only the symbols will be matching