hello everyone welcome to tutorials point in this video we are going to discuss about chapter number 10 that is circuit First of all, what is the importance of circle? And why we are discussing about circles? If you observe our surroundings, there are a lot of objects which are made in a circular shape.
Or at least they have circular impression on them. For example, if you start with the camera, the lenses of camera which are in a circular shape. And if you observe radio knobs which are also in circular shape.
The best example is a wheels. Can you imagine wheels with rectangular or triangular shape? No right? And if you observe our earth, the side view of earth is a circle.
So one way or other, circle is playing a major role in our day-to-day life. So that is the reason why we are discussing about circles. First of all, what is circle? We already read about circle in our 9th class. Circle is nothing but a collection of different different points on a plane which are fixed distance from a point.
Here this point is considered as a center. This is a center. And all this collection of points, it means the complete perimeter of circle is a collection of point and which are at fixed distance from the center.
And this fixed distance is nothing but a radius. So this is the exact definition of circle. And we also know the various terms of circle.
For example, here if I take two points on circle and if I join them with a line through this center, then it will become the diameter. Let's consider this point as A and this point as a B. And here AB is a diameter and if I take two more points on a circle and if I join them with a line and here the two endpoints of this line on the circle let's consider them as a point M point N here M and M this line is considered as a chord and if I take two more points here and here let's consider as a X and Y this small portion of this perimeter is called arc here XY is a arc This arc is nothing but a small portion of perimeter.
Here this card divide the circle into two portion. This is part 1 and this is the entire portion is part 2. And these two different parts which are divided by card is considered as a segment. and if I take another point, let's suppose let's take x and if I join with radius to the center and this portion which is in between two radius and arc is considered as a sector and guys these are the various terms of circle. Now, let us see the different situation arises when a circle and line is given.
Here, in our first case, a line and circle is given. And there is no common point between this line and this circle. For that reason, this line is considered as a non-intersecting line.
And here, in case 2, We have one common point between this line and this circle. Here, this common point is considered as a point of contact. And here, this line has only one common point with circle. That's why this line is considered as a tangent.
and here coming to our third case Here this line has two common points that is point 1 and point 2. For that reason this line is considered as a secant of circle. So guys these are the three situations which arises when a line and circle is given. TutorialsPoint.com Simply easy learning