
CBSE Class 10 Maths Notes Chapter 12: Get all of the class 10 notes on a topic about circles here. This page contains the following circle-related concepts: area, circumference, segment, sector, angle, length, and area for a circle's sector. Additionally, some plane and solid figure areas' visualisation is covered here.
We will study how to calculate the circumference, and length of an arc in a sector, areas of circles, areas of segments and sectors of circles, and other related concepts in the Class 10 chapter "Areas Related to Circles." A circle is a figure with two dimensions. All of the points on this curving form are equally spaced from the center. Now let's explore how to locate regions connected to the circle in this post.CBSE Class 10 Maths Notes Chapter 12 PDF
The perimeter of a circle has a special name: Circumference, which is π times the diameter which is given by the formula;
Circumference of a circle = 2πr.
Example: The circumference of a circle whose radius is 21cm is given by;
C = 2πr
= 2 (22/7) (21)
= 132 cm
CBSE Class 10 Syllabus 2024-25
( θ/360°) × π r 2where ∠ θ is the angle of this sector(minor sector in the following case) and r is its radius
Example: Suppose the sector of a circle is 45° and the radius is 4 cm, then the area of the sector will be:
Area = (θ/360°) × πr
2
= (45°/360°) × (22/7) × 4 × 4
= 44/7 sq. cm
The length of the arc of a sector can be found by using the expression for the circumference of a circle and the angle of the sector, using the following formula:
L = ( θ/360°) × 2 π rWhere θ is the angle of the sector and r is the radius of the circle.
Area of segment APB (highlighted in yellow)
= (Area of sector OAPB) – (Area of triangle AOB)
=[(∅/360°) × π r 2 ] – [(1/2) × A B ×OM][To find the area of triangle AOB, use trigonometric ratios to find OM (height) and AB (base)] Also, the area of segment APB can be calculated directly if the angle of the sector is known using the following formula.
= [(θ/360°) × π r 2 ] – [ r 2 ×sin θ/2 × cos θ/2 ]Where θ is the angle of the sector and r is the radius of the circle.
Area of a trapezium
=[
(a+b)×
h]/2
,
where
a
&
b
are the lengths of the parallel sides
h is the trapezium height
The area of a rhombus
=
pq/2,
where
p
&
q
are the diagonals.
