1
00:00:00,370 --> 00:00:07,629
Let's make a square. The first thing we need to decide is the size of the side

2
00:00:07,629 --> 00:00:15,689
of the square. I'm going to do it of 6 centimeters so from 0 to 6 I make a

3
00:00:15,689 --> 00:00:22,870
straight line or a segment with two vertex. I'm going to call this A and

4
00:00:22,870 --> 00:00:30,410
this B just to understand to make us understand each other's okay now I need

5
00:00:30,410 --> 00:00:43,630
to put 90 degrees over each point and I place this square with the I place the

6
00:00:43,630 --> 00:00:52,509
square with the hypotenuse behind the line and behind the hypotenuse I

7
00:00:52,509 --> 00:01:02,270
place the cartabon like this yeah I think we have seen already that and now

8
00:01:02,270 --> 00:01:14,010
I turn the square and when I slide the square all the lines I can draw in the

9
00:01:14,010 --> 00:01:19,969
hypotenuse are going to be perpendicular to this one but I only want to draw two

10
00:01:19,969 --> 00:01:26,870
I want to draw this over A, a perpendicular line over the point A, I'm

11
00:01:26,870 --> 00:01:36,049
going to do it longer, and over B. In this case it has to be shorter but it doesn't

12
00:01:36,049 --> 00:01:45,409
matter if I, with care, I do it a little bit longer. Now I take the compass, a good

13
00:01:45,409 --> 00:01:51,790
compass yeah and I place a needle in the compass on one of the edges of the

14
00:01:51,790 --> 00:02:01,370
first segment for example in B and I put the pencil in the other point in E and I

15
00:02:01,370 --> 00:02:10,849
make a short arch and a soft arch that cuts the perpendicular line in one

16
00:02:10,849 --> 00:02:20,090
point. This point is going to be C. And I repeat the same operation, placing the

17
00:02:20,090 --> 00:02:29,669
compass in A and with the same measure of 6 centimeters I cut the other

18
00:02:29,669 --> 00:02:36,289
perpendicular lines in this point that is going to be called D. Obviously I can

19
00:02:36,289 --> 00:02:44,889
measure it directly okay if I don't have a compass of oh I want just to measure from 6 to 0 for

20
00:02:44,889 --> 00:02:52,530
example yeah the measure of the other two two sides and now I join these two points and when

21
00:02:52,530 --> 00:03:03,430
I join it I check that there is a distance of six centimeters between them it is okay so now

22
00:03:03,430 --> 00:03:22,150
Now I have my perfect square, a polygonal figure made with four sides that measure the same and with 90 degrees in each corner, in each angle.