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The perimeter of a semi-circular protractor is 32.4 cm. Calculate the radius of the protractor in cm

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Important Questions on Circle

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Mathematics>Geometry>Circle>Semicircle
A wheel covers a distance of 1100 cm in one round. The daimeter of the wheel is:
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Mathematics>Geometry>Circle>Semicircle
A, B and C are three points on a circle such that the angles subtended by the chord AB and AC at the centre O are 110° and 130°, respectively. Then the value of ∠BAC is:
EASY
Mathematics>Geometry>Circle>Semicircle
A circular disc of area 0.64π m2 rolls down a length of 1.408 km. The number of revolutions it makes is: (Take π=227)
MEDIUM
Mathematics>Geometry>Circle>Semicircle
In a circle with centre O, AD is diameter and AC is a chord. Point B is on AC such that OB=7 cm and ∠OBA=60°. If ∠DOC=60°, then what is the length of BC?
HARD
Mathematics>Geometry>Circle>Semicircle
Consider a semicircle of radius 1 unit constructed on the diameter AB, and let O be its centre. Let C be a point on AO such that  AC : CO=2 : 1. Draw CD perpendicular to AO  with D on the semicircle. Draw OE perpendicular to AD with E on AD. Let OE and CD intersects at H. Then DH equals
EASY
Mathematics>Geometry>Circle>Semicircle
The chords AB and CD of a circle interest at E. If AE=12 cm, BE=20.25 cm and CE=3DE, then the length (in cm) of CE is:
HARD
Mathematics>Geometry>Circle>Semicircle
In a circle AB is a diameter and CD is a chord. AB and CD produced meet at a point P, outside the circle.If PD=15.3 cm, CD=11.9 cm and AP=30.6 cm, then the radius of the circle is :
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Mathematics>Geometry>Circle>Semicircle
ABCD is a cyclic quadrilateral such that AB is a diameter of the circle circumscribing it and ∠ADC=130∘. Then ∠BAC is equal to:
EASY
Mathematics>Geometry>Circle>Semicircle
Which among the following statements are certainly correct?
 
 
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Mathematics>Geometry>Circle>Semicircle

What is the circumference of the largest circle which can be inscribed in a square of side 14 cm? (π=227)

HARD
Mathematics>Geometry>Circle>Semicircle
Two circles of radii 15 cm and 10 cm intersect each other and the length of their common chord is 16 cm. What is the distance (in cm) between their centres?
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Mathematics>Geometry>Circle>Semicircle
If the perimeter of a semicircle is 36 cm, then its radius is
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Mathematics>Geometry>Circle>Semicircle
PA and PB are two tangents from a point P outside the circle with centre O at the points A and B on it. If ∠APB=130°, then ∠OAB is equal to:
EASY
Mathematics>Geometry>Circle>Semicircle
In a circle, chords PQ and TS are produced to meet at R. If RQ=14.4 cm, PQ=11.2 cm, and SR=12.8 cm, then the length of the chord TS is:
EASY
Mathematics>Geometry>Circle>Semicircle
The sides of a triangle are 56 cm, 90 cm and 106 cm The circumference of its circumcircle is:
EASY
Mathematics>Geometry>Circle>Semicircle
AB is a chord in a circle with centre O. AB is produced to C  such that BC is equal to the radius of the circle. C is joined to O and produced to meet the circle at D. If ∠ACD = 32°, then the measure of ∠AODis ______.
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Mathematics>Geometry>Circle>Semicircle
P is a point outside a circle and is away 26 cm from its centre. A secant PAB drawn from P intersects the circle at point A and B such that PB = 32 cm and PA = 18 cm. The radius of the circle (in cm) is _____.
EASY
Mathematics>Geometry>Circle>Semicircle
Two circles of the same radius intersect each other at P and Q. If the length of the common chord is 30 cm and the distance between the centres of the two circles is 40 cm, then what is the radius (in cm) of the circles?
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Mathematics>Geometry>Circle>Semicircle
The wall around a semicircular garden is 180 m long. The area of the garden is (Take π=227)
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Mathematics>Geometry>Circle>Semicircle

In the given figure, ABCDE is a pentagon inscribed in a circle such that AC is a diameter and side BC∥AE. If ∠BAC=50°, find giving reason ∠ACB.

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