 Hi friends welcome again, so in the last couple of sessions we talked about definition of circle We talked about arc of a circle. We talked about major or minor arc the central angle in this session We are going to talk about other features and other parts of the circle Namely card segment secant arc sector and all that. Okay, so let's first draw a circle So point a is the center be AB is the radius. So let me join the AB Segment so AB is the radius and you can measure this Segment also. So if you see this segment is six unit long Okay, now what are we going to discuss is first thing is we were going to discuss about chords guys So chord is nothing but a segment joining two points on the circle. So let's say these two points CD So CD is a chord. Okay, what is a chord? The chord is nothing but a line segment joining Amy two points on the circle, right neither interior not exterior on the circle now if this chord let me just Take this point D and start moving it and let's see what happens So if you see there is one case when it is passing through the center when it is passing through the center this particular thing This particular case when the chord CD is passing through the center is called the diameter So CD is the diameter. Okay, so you can have infinitely many diameters, isn't it? So if you see one point here and then Like that. So this is another diameter then if I take this point here and Yeah, so you can see there are Thousands not thousands billions million trillion zillions. How may however you can think of These many diameters are there so diameter, right? Now another interesting point about this chord. What is it? If you see as I move away from center Keeping one point fixed it lengths keeps length Keeps on changing. Let's evaluate this as well. So let me say This is 3.93. Right now if I You know if I reduce it, you know, it is close going closer to Point C. So the value the length CD is changing and as these moving away as CD is moving away the length of CD is increasing. Can you see that? Can you see that 11.97 97 9 9 9 12? So the moment it passes through the center it becomes 12 correct and as again It moves away Moves away from the center the value starts decreasing decreasing decreasing decreasing decreasing and finally ends up being zero So hence what do we learn from this that the chord which passes through the center is the longest and hence We can define the dia as the longest chord as well, isn't it? So as the chord is Moving or let's say the length is changing as it moves closer to the center Okay, it is You know if it passes through the center it is having the maximum length Right. This is called diameter guys. Okay, so you understood what is a chord. What is a diameter now? So the diameter divides the two circle Sorry, the given circle into two halves and each half is called the semi circle You know this already. So for example C to E B G D So from D to G then B then E then C this part this part is called semi circle Similarly C H F D. This part is also another semi circle. Is that okay guys? So this is there are two one diameter divides a circle into two equal parts They're called semi circle. Now. Let's talk about something else something else. So hence, let me just Take this away. Okay, take this away and hide it Okay. Now once again if you now focus on let's say the CD chord now chord CD is dividing the circle into two halves. Can you see so one is Above the CD segment one is below the CD segment So if I have to you know, this one is one part this part and this lower part is another part, right? Now this part the bigger area part in which the center lies is called Major segment. So let me you know Write it out. So it's called So it is major Segment Okay, this is major segment. Okay. So what is major segment? This is major segment. What is minor segment? Let me write minor segment Segment, okay, so where is minor segment? This is minor segment guys Okay, so the major segment carries the center the center minor segment doesn't carry the center. Okay another You know a parts or let's attributes of circle is this so let's say if you have a line Let's say I have a line which cuts the Circle so a line can cut a circle in you know three ways one where it is cutting in two points So can you see that so? This point is your K and L, right? K and L. So So L is not the point just a minute mark the point. So hence if you see yeah, K and L K and L are the points. Okay, so this line can This line is cutting through the circle at two points. So if I If L is coming close to K. So if you see What happens is it touches the circle exactly at one point right this particular case when the line is touching the circle exactly at one point is Called the tangent. So this line is called tangent. So let me write it is tangent Okay, so this line is tangent guys, okay, and any other line Passing like that which it cuts into two which cuts the circle at two points is called a secant Okay, so this line is called Secant tangent is done secant is done major segment minor segment chord diameter radius all that you learned Is it okay? So this is what we are going to deal with all these you know definitions and attributes we're going to discuss more on the properties of circles one another thing which I missed on Missed to tell you is the same line. They can they can exist a line which doesn't Touch or cut the circle at all. So hence there are three possible. There are three possibilities for sorry for interaction between a circle and a line Either it doesn't they don't touch each other each other or the tank or the line Touches the circle exactly at one point when it is called a tangent. So don't get confused. This is the tangent not This is this general line is not the tangent. So Tangent This line is tangent Okay, and a line can also cut the circle at two points In that case it is called a secant. Okay, so please Remember these facts