# Case Study Chapter 11 Areas related to Circles Mathematics

Refer to Case Study Chapter 11 Areas related to Circles Mathematics, these class 10 maths case study based questions have been designed as per the latest examination guidelines issued for the current academic year by CBSE, NCERT, KVS. Students should go through these solves case studies so that they are able to understand the pattern of questions expected in exams and get good marks.

## Chapter 11 Areas related to Circles Mathematics Case Study Based Questions

l. Read the following and answer The art department of a school prepared circular hanging for the annual function of the school. The circle with diameter 42 cm was placed at the bottom and the size of the middle circle was half the size of the bottom one and the smallest circle was half the size of the middle circle.

Question. The area of the bottom circular region that is visible is
(a) 1323/2 πcm2
(b) 1323/4 πcm 2
(c) 245π cm2
(d) 340π cm2

B

Question. The ratio of the areas of the three circles, starting from the bottom circle is
(a) 16: 4 : 1
(b) 4 : 2 : 1
(c) 1: 2 : 4
(d) 1 : 4 : 16

A

Question. A colourful tape was used to decorate the boundary of the bottom circle. The length of tape used is
(a) 42 cm
(b) 42π cm
(c) 21 cm
(d) 21π cm

B

Question. The radius of the smallest circle is
(a) 7 cm
(b) 14 cm
(c) 10.5 cm
(d) 5.25 cm

D

Question. The area of the middle circle is
(a) 154 cm2
(b) 616 cm2
(c) 346.5 cm2
(d) 1386 cm2

C

ll. Read the following and answer Gauri got her wall painted in a different manner. The whole wall was painted pink, leaving a circular portion of diameter 4.2m. In this circle, she asked the painter to paint a beautiful scenery in one half of it by drawing a full size triangle possible (as shown in the figure). In the other half of the circle, she drew the largest circle possible and pasted some of her pictures. The remaining part of the big circle was filled with dotted design.

Question. The area of the wall that is not painted pink is given by
(a) (96 – 4.41π) m2
(b) (40 – 4.41π) m2
(c) (96 – 17.64π) m2
(d) (40 – 17.641π) m2

A

Question. The area of the dotted design is approximately
(a) 10 m2
(b) 6 m2
(c) 9 m2
(d) 8 m2

B

Question. The cost of designing the whole circular region at the rate of ` 80 per m2 is
(a) ₹ 4,435.2
(b) ₹ 110.88
(c) ₹ 1,108.80
(d) ₹ 346.50

C

Question. The area of the triangular region is
(a) 4.41 m2
(b) 8.82 m2
(c) 2.205 m2
(d) 17.64 m2

A

Question. The radius of the circle allotted for her pictures is
(a) 4.2 m
(b) 2.1 m
(c) 1.05m
(d) cannot be determined

C

lll. Read the following and answer Raghav was standing outside his home. He then tried to find how many times does the wheel of the car move in a certain time.

Question. The number of revolutions made by the wheel in eleven minutes is
(a) 31
(b) 32
(c) 18
(d) 25

A

Question. If the circumference and the area of a circle are numerically equal, then diameter of the circle is
(a) 2 units
(b) 4 units
(c) 6 units
(d) 1 unit

B

Question. The area of a circular ring formed by the circles of radii a and b respectively is given by
(a) 2π (a – b)
(b) 2π (a2 – b2)
(c) π (a2 – b2)
(d) π (a2 + b2)

C

Question. Raghav measured the diameter of his car’s wheel and found it to be 84 cm. The distance travelled by the wheel in one revolution is
(a) 84π cm
(b) 42π cm
(c) 21π cm
(d) 176π cm

A

Question. He observed that an average speed of car in front of his house is 45 km/h. The distance travelled in 1 minute is
(a) 450 m
(b) 750 m
(c) 500 m
(d) 760 m

B

lV. Read the following and answer A horse and an ox are tied to a peg at opposite corners of a rectangular field of dimensions 35 m × 20 m by ropes of length 5 m and 10 m respectively. (use π = 3.14)

Question. The area of the field left to be grazed is
(a) 700 – 125π /2 m2
(b) 700 – 125π/4 m
(c) 110 – 125π/2 m
(d) 110 – 125π/4 m

B

Question. If the rope to which horse is tied would have been 8 m long, then the increase in the grazing area is given by
(a) 39/4 π m2
(b) 35/4 π m2
(c) 37/2 π m2
(d) 35/2 π m2

A

Question. The area of a sector of a circle bounded by an arc of length 5π cm is equal to 20r cm2, then its radius is
(a) 12 cm
(b) 16 cm
(c) 8 cm
(d) 10 cm

C

Question. The area of the field that the horse can graze is given by
(a) 25π m2
(b) 10π m2
(c) 25/2 π m2
(d) 25/4 π m2