Circles
Circles
Circles
CHAPTER 10
Circle
(a) 5 (b) 5 2
2 6. In figure, AP , AQ and BC are tangents of the circle
(c) 10 2 (d) 10 3
Sol : [Board 2020 OD Basic]
with centre O . If AB = 5 cm , AC = 6 cm and BC = 4
cm, then the length of AP (in cm) is
(a) 30 cm (b) 28 cm
(c) 32 cm (d) 25 cm
Sol : [Board 2020 Delhi Basic]
(a) 28c (b) 32c
(c) 42c (d) 38c
9. Two circles of radii 20 cm and 37 cm intersect in A Sol :
and B . If O1 and O2 are their centres and AB = 24 cm,
then the distance O1 O2 is equal to
(a) 44 cm (b) 51 cm 13. Two concentric circles of radii a and b where a > b,
The length of a chord of the larger circle which touches
(c) 40.5 cm (d) 45 cm the other circle is
Sol :
(a) a2 + b2 (b) 2 a2 + b2
10. In the adjoining figure, TP and TQ are the two (c) a2 - b2 (d) 2 a2 - b2
Sol :
tangents to a circle with centre O . If +POQ = 110c,
then +PTQ is
14. In the given figure, a circle touches all the four sides
of quadrilateral ABCD with AB = 6 cm , BC = 7 cm
and CD = 4 cm , then length of AD is
15. Two concentric circles are of radii 10 cm and 8 cm, PR = 8 cm and QR = 12 cm , then the diameter of the
then the length of the chord of the larger circle which largest circle is:
touches the smaller circle is
(a) 6 cm (b) 12 cm
(c) 18 cm (d) 9 cm
Sol :
(a) 30 cm (b) 20 cm
(c) 10 cm (d) None of these
Sol :
(a) 4 cm (b) 2 cm 28. In the adjoining figure, TP and TQ are the two
(c) 2 3 cm (d) 4 3 cm tangents to a circle with centre O . If +POQ = 110c,
Sol : then find the angle +PTQ .
24. QP is a tangent to a circle with centre O at a point P 29. In figure, AP , AQ and BC are tangents of the circle
on the circle. If TOPQ is isosceles, then find +OQR with centre O . If AB = 5 cm , AC = 6 cm and BC = 4
? cm, then what is the length of AP ?
Sol : [Board 2020 Delhi Basic]
Sol : [Board 2020 Delhi Basic] 31. Two circles of radii 20 cm and 37 cm intersect in A
and B . If O1 and O2 are their centres and AB = 24 cm,
27. In figure, O is the centre of circle. PQ is a chord and then find the distance O1 O2 .
Sol : [Board Term-2 Foreign 2016]
PT is tangent at P which makes an angle of 50c with
PQ . Find the angle +POQ .
32. In the figure, QR is a common tangent to given circle
which meet at T . Tangent at T meets QR at P . If
QP = 3.8 cm, then find length of QR .
33. Two concentric circles of radii a and b where a > b, 39. In given figure, if +AOB = 125c, then find the angle
Find the length of a chord of the larger circle which +COD ?
touches the other circle.
Sol : [Board Term-2 OD 2015]
40. In the given figure, a circle touches all the four sides
of quadrilateral ABCD with AB = 6 cm , BC = 7 cm
and CD = 4 cm , then what is the length of AD ?
43. What is the maximum number of parallel tangents a 49. In the given figure, PQ and PR are tangents to the
circle can have on a diameter? circle with centre O such that +QPR = 50º, Then
Sol : [Board Term-2 2012]
find +OQR.
Sol : [Board Term-2 Delhi 2014] 53. PA and PB are tangents from point P to the circle
with centre O as shown in figure. At point M , a
48. If a line intersects a circle in two distinct points, what
is it called ?
Sol : [Board Term-2, 2012]
Page 124 Circle Chap 10
tangent is drawn cutting PA at K and PB at N . 57. In the given figure, find +QSR .
Prove that KN = AK + BN
Sol : [Board Term-2, 2012] 58. In figure, AP and BP are tangents to a circle with
centre O , such that AP = 5 cm and +APB = 60c.
Find the length of chord AB .
54. PQ is a tangent drawn from an external point P
to a circle with centre O , QOR is the diameter of
the circle. If +POR = 120c, What is the measure of
+OPQ ?
Sol : [Board Term-2 Foreign 2017] Sol : [Board Term-2 Delhi 2016]
60. In figure, O is the centre of the circle, PQ is a chord 64. In the given figure, from a point P , two tangents PT
and PT is tangent to the circle at P . Find +OPQ and PS are drawn to a circle with centre O such that
and +TPQ +SPT = 120c, Prove that OP = 2PS .
TWO MARKS QUESTION 65. From an external point P , tangents PA and PB are
drawn to a circle with centre O. If +PAB = 50º, then
find +AOB.
Sol : [Board Term-2 Delhi 2016]
61. A circle is inscribed in a TABC touching AB , BC
and AC at P , Q and R respectively. If AB = 10 cm
AR = 7 cm and CR = 5 cm , then find the length of 66. In given figure, AB is the diameter of a circle with
BC centre O and AT is a tangent. If +AOQ = 58c, find
Sol : [Board 2020 OD Basic] +ATQ .
69. In figure, two tangents RQ and RP are drawn from 73. In Figure, common tangents AB and CD to the two
an external point R to the circle with centre O . If circle with centres O1 and O2 intersect at E. Prove
+PRQ = 120c, then prove that OR = PR + RQ . that AB = CD.
80. Prove that the rectangle circumscribing a circle is a Sol : [Board 2020 OD Basic, 2020 Delhi Standard]
square.
Sol : [Board 2020 SQP Standard]
87. If O is centre of a circle, PQ is a chord and the 92. Prove that the tangents drawn at the ends of a
tangent PR at P makes an angle of 50c with PQ , diameter of a circle are parallel.
find +POQ . Sol : [Board 2020 Delhi Basic, 2017, 2014]
97. a, b and c are the sides of a right triangle, where c 100. In figure, a circle with centre O is inscribed in a
is the hypotenuse. A circle, of radius r , touches the quadrilateral ABCD such that, it touches the sides
sides of the triangle. Prove that r = a + b − c . BC , AB, AD and CD at points P, Q, R and S
Sol : 2 Term-2 Delhi 2016]
[Board respectively. If AB = 29 cm, AD = 23 cm, +B = 90c
and DS = 5 cm, then find the radius of the circle.
98. PB is a tangent to the circle with centre O to B.AB
is a chord of length 24 cm at a distance of 5 cm from
the centre. It the tangent is length 20 cm, find the
length of PO .
99. In figure O is the centre of a circle of radius 5 cm. T 103. Two tangents PA and PB are drawn from an
is a point such that OT = 13 cm and OT intersects external point P to a circle with centre O , such that
circle at E . If AB is a tangent to the circle at E , find +APB = +x and +AOB = y . Prove that opposite
the length of AB , where TP and TQ are two tangents angles are supplementary.
to the circle. Sol : [Board Term-2, 2011]
106. In the given figure, O is the centre of the circle. 109. In Figure, PQ and RS are two parallel tangents to
Determine +APC , if DA and DC are tangents and a circle with centre O and another tangent AB with
+ADC = 50c. point of contact C intersecting PQ at A and RS at
B . Prove that +AOB = 90c.
113. In the figureAB and CD are common tangents to two 116. In the given figure, PA and PB are tangents to
circles of unequal radii. Prove that AB = CD . the circle from an external point P . CD is another
tangent touching the circle at Q . If PA = 12 cm,
QC = QD = 3 cm, then find PC + PD.
114. In figure PQ is a tangent from an external point P Sol : [Board Term-2 Delhi Compt. 2017]
to a circle with centre O and OP cuts the circle at T
and +QOR is a diameter. If +POR = 130c and S is COMPETENCEY BASED QUESTION
a point on the circle, find +1 + +2 .