Segment of a circle Formed by a Secant
Segments
The last part of a circle that we can find the area of is called a segment, not to be confused with a line segment. A segment of a circle is the area of a circle that is bounded by a chord and the arc with the same endpoints as the chord.
Now let us take the case of the area of the segment APB of a circle with centre O and radius r.
We can see that :
Area of the segment APB = Area of the sector OAPB – Area of ∆ OAB
=
We can also observe that :
Area of the major sector OAQB =
Area of major segment AQB =
2. Find the area of the segment AYB, if radius of the circle is 21 cm and ∠AOB= 120°.
- Area of the segment AYB = Area of sector OAYB – Area of △OAB
- Now, finding the area of the sector OAYB, we get:
- Calculate the segment then we get the answer is equal to
cm 2 - We have found the answer.