Area Problems In a circle of radius 21 cm an arc subtends an angle of 72° at the centre. The length of the arc is? 26.4 cm 21.6 cm 19.8 cm 13.2 cm 26.4 cm 21.6 cm 19.8 cm 13.2 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Arc length = 2?r (?° / 360°) = 2 x (22/7) x 21 x (72° / 360°) cm= 26.4 cm
Area Problems Find the length of a rope by which a cow must be tethered in order that it may be able to graze an area of 9856 sq meters. 76m 16m 56m 14m 76m 16m 56m 14m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP clearly the cow will graze a circular field of area 9856 sq m and radius equal to the length of the rope. Let the length of the rope be r mts then, r2 = 9856 r2 = (9856 × 7) / 22 = 3136 r = 56 m
Area Problems The area of a rectangle is 460 square metres. If the length is 15% more than the breadth, what is the breadth of the rectangular field? 20 m 30 m 40 m 50 m 20 m 30 m 40 m 50 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let breadth = x meters. Then, Length = 115x / 100 meters Given that, X × (115X / 100) = 460 => X = 20
Area Problems The ratio of the area of square of side a and equilateral triangle of side a is? 2 :1 2 : ?3 4 : ?3 4 :3 2 :1 2 : ?3 4 : ?3 4 :3 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of area = a2/ ?(3/4) a2= 4/?3 = 4:?3
Area Problems A rectangular field is to be fenced on three sides leaving a side of 20 feet uncovered. If the area of the field is 680 sq. feet, how many feet of fencing will be required? 40 68 88 34 40 68 88 34 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP We have: l = 20 ft and lb = 680 sq. ft. So, b = 34 ft. ∴ Length of fencing = (l + 2b) = (20 + 68) ft = 88 ft
Area Problems The inner circumference of a circular race track, 14 m wide is 440 m . Then the radius of the outer circle is? 56 m 70 m 77 m 84 m 56 m 70 m 77 m 84 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circumference of a circular = 2?r? 2 x (22 / 7) x r = 440? r = [440 x (7/22) x (1/2)] = 70 m? Radius of outer circle = (70 + 14) m = 84 m
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