Draw a Circle and Label All Its Parts

What are the Parts of a Circle

And then far, we take discussed about the triangle and quadrilateral that have linear boundaries. Circle is a closed effigy that has a curvilinear boundary.
When nosotros retrieve of circles, the very showtime thing that comes to our mind is its circular shape, for instance, bangles, coins, rings, plates, chapattis, pizzas, CDs etc. Wheels of a car, double-decker, cycle, truck, train, and plane are also round in shape. If nosotros take a stone, tie information technology to 1 end of a cord and swing it in the air by holding the other end of the string, the path traced by the rock will be a round path and information technology will make a circle.

Read More:

• Perimeter of A Circle
• Common Chord of Two Intersecting Circles
• Construction of a Circle
• The Expanse of A Circle
• Properties of Circles
• Sector of A Circle
• The Area of A Segment of A Circumvolve
• The Area of A Sector of A Circle
• Classification of triangles

1. Circle: A circle is a collection of all those points in a aeroplane that are at a given constant distance from a given fixed point in the plane.
2. Centre: Circumvolve is a airtight figure made upward of points in a airplane that are at the same distance from a fixed betoken, called the middle of the circle. In the figure O is the centre.
   

1. Radius: The abiding distance from its centre is called the radius of the circumvolve. In the figure, OA is radius
   
2. Chord:A line segment joining two points on a circumvolve is called a chord of the circle. In the figure, AB is a chord of the circle. If a chord passes through centre then it is longest chord. PQ, PR, and ST are chords of the circle. Chord ST passes through the centre, hence information technology is a diameter.
   
3. Diameter: A chord passing through the eye of a circle is chosen the diameter of the circumvolve. A circle has an infinite number of diameters. CD is the diameter of the circle equally shown in the figure. If d is the diameter of the circle then d = 2r. where r is the radius. or the longest chord is called bore.
   In the figure, AB is the diameter and the arcs CD and DC are semicircles.
   
4. Arc: A continuous piece of a circle is chosen an arc. Let A,B,C,D,E,F be the points on the circumvolve. The circle is divided into different pieces. Then, the pieces AB, BC, CD, DE, EF etc. are all arcs of the circle.
   Let P,Q be ii points on the circle. These P, Q split up the circle into two parts. Each part is an arc. These arcs are denoted in anti-clockwise direction
   
5. Circumference of a circumvolve:The perimeter of a circumvolve is called its circumference. The circumference of a circle of radius r is 2πr.
6. Semicircle: The diameter of a circle divides the circle into 2 equal parts. Each office is called a semi-circle. Nosotros can also say that half of a circle is called a semi¬circle. In the figure,  AXB and AYB represents ii semi-circles.
7. Segment: Permit AB be a chord of the circle. Then, AB divides the region enclosed past the circle (i.east., the circular disc) into ii parts. Each of the parts is called a segment of the circle. The segment, containing the modest arc is called minor segment and the segment, containing the major arc, is called the major segment and segment of a circumvolve is the region betwixt an arc and chord of the circle.
   
8. Central Angles: Consider a circle. The angle subtended by an arc at the centre O is called the key angle. The vertex of the central angle is always at the centre O.
   
9. Degree measure of an arc: Caste measure out of a minor arc is the measure of the central angle subtended by the arc.
   
   The degree measure of the circumference of the circle is always 360°.
10. Interior and Outside of Circle
    A circle divides the plane on which lies into three parts.
    (i) Inside the circumvolve. which is called the interior of the circle
    (2) Circle
    (iii) Outside the circle, which is called the exterior of the circumvolve.
    The circle and its interior make up the round region.
    
11. Sector:
    A sector is that region of a circular disc which lies between an arc and the two radii joining the extremities of the arc and the center. OAB is a sector as shown in the figure.
    Quadrant: One 4th of a circular disc is called a quadrant.
    
12. Position of a point:
    Betoken Inside the circumvolve: A point P, such that OP < r, is said to lie inside the circumvolve.
    The point inside the circumvolve is also called interior betoken. (Instance : Centre of cirle)
    Bespeak outside the circle: A point Q, such that OQ > r, is said to prevarication outside the circle C (O, r) = {X, OX = r}
    The indicate outside the circle is also chosen exterior point.
    Point on the circle: A point S, such that Bone = r is said to prevarication on the circle C(O, r) = {X ,OX = r}.
    Circular Disc: It is defined equally a set of interior points and points on the circle. In set note, it is written as : C(O, r) = {X : P OX ≤ r}
    
13. Concentric Circles:
    Circles having the same centre and dissimilar radius are said to be concentric circles.
    Remark. The word 'radius' is used for a line segment joining the heart to whatever point on the circle and also for its length.
    
14. Congruence of Circles & Arcs
    Congruent circles: 2 circles are said to be congruent if and just if, one of them tin exist superposed on the other, so as the encompass it exactly. It means ii circles are congruent if and merely if, their radii are equal. i.e., C (O, r) and C (O' , r) are congruent if only if r = due south.
    Coinciding arcs: Ii arcs of a circle are coinciding, if either of them can be superposed on the other, so as to embrace it exactly. It is only possible, if caste mensurate of two arcs are the same.

Example 1: Take two points A and B on a plane canvas. Draw a circle with A as a heart, Ac equally radius and B in its exterior.
Solution: Marking two points A and B on a paper.
A •            • B
Every bit the point B should be in the exterior of the circle, take A every bit the middle and radius (r) less than AB to depict a circumvolve.

Instance 2 :Find the diameter of the circle of radius half dozen cm.
Solution: We know,
Diameter = 2 × radius
∴ Diameter =2 × half dozen cm =12 cm

huguleypostard.blogspot.com

Source: https://www.aplustopper.com/parts-of-the-circle/

Share this post