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A circle is the set of points in a plane that are in same distant from a center. A circle is named by its center.
The distance from the centre of the circle to any point on a circle is called the radius of the circle.
In the given figure, O is the centre and OA is a radius of the circle.
The diameter of a circle is the distance across a circle through the center.
In the figure, BA is a diameter.
A chord is a line segment that joins two endpoints that lie on a circle. A circle has many different chords.
In the figure, AB is a chord of the circle.
Circumference is the distance once around the circle. And a part of the circumference is called an Arc.
In the given figure, the smaller part CXB is known as the minor arc and the greater part CYB is known as the major arc.
A slice of a pizza can be known as a sector of a circle. There are especially two types of a sector in circle: Quadrant and Semicircle.
A quarter of a circle is called a Quadrant.
Half a circle is called a Semicircle.
A chord divides the circle into two parts and the parts made by a chord is called a Segment.
The smaller part is called the minor segment and the other part is called the major segment.
An inscribed angle is an angle formed by two chords in a circle which has a common endpoint. This common endpoint forms the vertex of the inscribed angle and the corresponding arc is called the intercepted arc. In the figure, ABC is an inscribed angle and AC is called an intercepted arc.
Two circles may intersect in two imaginary points that may a single degenerate point or two distinct points.
In the figure, two circle are intersect where, AB is the common chord of the circles with centre O and P.
Concentric circles are simply a circles with a same distance apart all the way aroundwith a common center.
In the figure, three circles have the same centre O, so the circles are concentric.
A cyclic quadrilateral is a quadrilateral whose all polygon vertex touches the circumference of a circle.
In the above figure, only in fig (iii) ABCD is cyclic quadrilateral and vertices A, B, C and D are concyclic.
Secant is a line that intersects the circle at two distinct points.
In the figure, the line XY is a secant.
A line that touches a circle at just one point is a tangent.In the figure, AB is a tangent to the circle at C. The point C is called the point of contact.
At most two tangent can be drawn to the circle from an external point.
Solution:
Here,
\(\pi\)= 3.14
Diameter of circle(d) =10 inch
Circumference of circle (c)= ?
By using formula,
c = \(\pi\) d
= 3.14×10 inch
= 31.4 inch
Solution:
Here,
\(\pi\)= 3.14
Radius of a circle(r)=12 m
Circumference of circle (c)= ?
By using formula,
c =2\(\pi\) r
=2×3.14×12 m
=75.36 m
Solution:
Here,
\(\pi\)= 3.14
Diameter of a circle(d) = 18 ft
Circumference of circle(c )= ?
By using formula,
c = \(\pi\)d
=3.14 × 18bft
= 56.52 ft
Solution:
Here,
\(\pi\)= 3.14
Circumference of circle(C)=65.94 ft
Radius(r)=?
We know that,
C=2\(\pi\)r
or, 65.94=2×3.14×r
or, 6.28×r=65.94
or, r=\(\frac{65.94}{6.28}\)
or, r=10.5
∴ Radius(r)= 10.5 ft
Solution:
Here,
\(\pi\)=\(\frac{22}{7}\)
Radius of a circular stadium(r) = 100m
Circumference (C)=?
We know that,
C = 2\(\pi\)r
=2×3.14×100
=628m
∴ Radius of a circular stadium is 628m
Solution:
Here, \(\pi\)=\(\frac{22}{7}\)
Radius of a circle(r)= 3 cm
Area of a circle(A)=?
By using formula,
A=\(\pi\)r^{2}
=3.14×(3)^{2}
=28.26 cm^{2}
Hence, Area of a circle = 28.26 cm^{2}
Solution:
Here,
\(\pi\)=3.14
Diameter of a circle(d)= 5 cm
Radius of a circle(r)=\(\frac{d}{2}\)=\(\frac{5}{2}\)=2.5 cm
Area of a circle(A)=?
By using formula
A=\(\pi\)r^{2}
=3.14×(2.5)^{2}
=19.625 cm^{2}
Hence, Area of a circle(A)=19.625 cm^{2}
Solution:
Here,
\(\pi\)= 3.14
Radius of a circle(r)=8 ft.
Area of a circle(A)=?
By using formula,
A=\(\pi\)r^{2}
=3.14×(8)^{2}
=200.96 ft^{2}
Hence, Area of a circle(A)=200.96 ft^{2}
Solution:
Here,
\(\pi\)=3.14
Diameter of a circle=(d)=12 inch
Radius of a circle(r)=\(\frac{d}{2}\)
=\(\frac{12}{2}\)
= 6 inch
Area of a circle(A)=?
By using formula,
A=\(\pi\)r^{2}
=3.14×(6)^{2}
=113.04 inch^{2}
Hence, Area of a circle(A)=113.04 inch^{2}
Solution:
Here,
\(\pi\)= 3.14
Diameter of a circle(d)=15 mm
Radius of a circle(r)=\(\frac{d}{2}\)
=\(\frac{15}{2}\)
=7.5 mm
Area of a circle(A)=?
By using formula
A = \(\pi\)r^{2}
=3.14×(7.5)^{2}
=176.625 mm
Hence, Area of a circle(A)=176.625 sq.mm
Solution:
Here,
\(\pi\)= 3.14
Diameter of a circle(d)=22 cm
Radius of a circle(r)=\(\frac{d}{2}\)
=\(\frac{22}{2}\)
=11 cm
Area of a circle(A)= ?
By using formula,
A= \(\pi\)r^{2}
=3.14×(11)^{2}
=379.94 cm^{2}
Hence, Area of a circle (A)=379.94 cm^{2}
Find the radius of a circle whose circumference is 44cm.
A wire in the form of the rectangle 18.7 cm long and 14.3 cm wide is reshaped and bent into the form of a circle. Find the radius of the circle formed.
Find the diameter of a circle whose circumference is 57.2.
The diameter of the wheel of a car is 77cm. How many revolutions will it make to travel 121 km?
Find the distance covered by the wheel of a car in 2000 rotations if the diameter of the wheel is 98cm.
Find the circumference of a circle whose radius is 14cm.
Find the circumference of a circle whose diameter is, 28cm.
Find the area of the circular region whose radius is, 56m.
Find the area of a circular park whose circumstance is 264m.
The circumference of a circle is 35.2m. Find its area.
The area of a circle is 616m^{2}.Find its radius.
Find the area of a circular region whose diameter is 2.1.
The area of a circle is 154cm^{2}.Find its circumference.
Find the circumstances of a circle whose area is 2464m^{2}.
Find the circumference of a circle whose radius is 7cm.
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Sushrut
Hi ande
Jan 18, 2017
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unknown
how to find diameter if circumfernce is given??plz reply fastet
Jan 17, 2017
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Radiud
A wheel goes 110m far in 5 revolutions. Find the radius
Jan 17, 2017
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