Circumference of a circle and Formula
If a circle is opened to make a line then length of that line are going to be the circle’s circumference.
How to calculate the circumference of the circle?
For calculating the circumference of a circle, multiply the diameter of the circle with π (pi). The circumference also can be calculated by multiplying 2×radius with pi (π=3.14).
What is radius?
The radius of a circle is that the length of the line from the middle to any point on its edge.
Circumference with radius
As radius is half diameter than
R=d/2
and circumference is
C=πd
Formula for circumference is when radius is given
C=2πr
Put values in the formula and find circumference.
What is the unit of circumference?
Circumference, like perimeter, is measured in linear units centimeters, inches, feet, yards, meters, kilometers, miles, etc.
Value of pi π?
After division of circumference by the diameter we get 3.141592654…
which is that the number π (Pi)
What is Area of circle?
Circle’s area is π times the radius squared, which is written:
A = π r2
Where
A is Area
r is radius
What are the special names of lines?
A line that “just touches” the circle because it passes by is named as Tangent.
A line that cuts the circle at two points is named as Secant.
A line segment that goes from one point to a different one on the circle’s circumference is named as a Chord.
If it passes through a middle it is known as Diameter.
And which is near the circumference is called an Arc.
How many slices of the circle?
There are two main “slices” of a circle.The “pizza” slice is named a Sector and the slice made by a chord is named a Segment.
What are common sectors?
Two special types of Sectors are Quadrant and Semicircle.
Quarter of a circle is called a Quadrant.
Half a circle is called a Semicircle.
Angle of sector from center with180° is named a half-disk and is bounded by a diameter and a semicircle. Angles of sectors from center are sometimes given special names, these include quadrants (90°), sextants (60°) and octants (45°), which come from the sector being one 4th, 6th or 8th a part of a full circle, respectively. Confusingly, the arc of a quadrant also can be termed a quadrant.
What is arc length?
Formula for the length of an arc is
L=rθ
L denotes the arc length, r denotes the radius of the circle and θ denotes the angle in radians made by the arc at the centre of the circle.
What is the length of chord?
Chord’s length formed with the extremal points of the arc is given by
C=2R θ/2
C denotes the chord length, R represents the radius of the circle, and θ represents the angular width of the sector in radians.
Area of a sector of a circle?
Finding the area of a sector, actually finding a fractional part of the area of the entire circle. The fraction is find by the ratio of the central angle of the sector to the “entire central angle” of 360 degrees.
Find the area of a sector by expressing the fraction is possible when
ratio of the arc length (s) to the whole circumference.