Area Problems The circumferences of two concentric are 176 m and 132 m respectively. what is the difference between their radii? 8 meter 5 meter 7 meter 44 meter 8 meter 5 meter 7 meter 44 meter ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 2?R - 2?r = (176-132)? 2?(R-r) = 44? R-r = ( 44 x 7 )/ (2 x 22)= 7 m
Area Problems In a triangle ABC, BC = 5 cm AC = 12 cm and AB = 13 cm. The length of a altitude drawn from B on AC is? 4 cm 5 cm 7 cm 6 cm 4 cm 5 cm 7 cm 6 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? s= (13 + 5 + 12) / 2 cm = 15cms-a = 2 cm, s-b = 10 cm and s-c = 3 cm ? Area = ? (15 x 2 x 10 x 3 ) cm2= 30 cm2? (12 x h) / 2 = 30 ? h = 5 cm
Area Problems A rectangle has 15 cm as its length and 150 cm 2 as its area .Its area is increased to 1 1 / 3 times the original area by increasing only its length . Its new perimeter is? 60 cm 50 cm 80 cm 70 cm 60 cm 50 cm 80 cm 70 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Breadth of the rectangle = (150/15) cm= 10 cmNew area = (4/3 x 150) cm2= 200 cm2New length = 200/10 cm=20 cmNew perimeters = 2(20 + 10) cm= 60 cm
Area Problems A rectangular plot is half as long again as it broad. The area of the lawn is 2/3 hectares. The length of the plot is? 33 meters (100/ ? 3 ) meters 66.66 meters 100 meters 33 meters (100/ ? 3 ) meters 66.66 meters 100 meters ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let breadth = b meters. then, length = 3b/2 meters ? b x 3b/2 = 2/3 X 10000? b2 = (4 x 10000)/9? b = ( 2 X 100)/3 m ? Length = (3/2) x (2/3) x 100 m= 100 m
Area Problems A rectangle has 20 cm as its length and 200 sq cm as its area. If the area is increased by 1 1/ 5 time the original area by increase its length only then the perimeter of the rectangle so formed (in cm) is 68 60 72 64 68 60 72 64 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP l1 = 20 cm, A1 = 200 sq cm? b1 = 200/20 = 10 cmNow, A2 = 200 x 6/5 = 240 sq cm b2 = 10 cm? l2 = 240/10 = 24 cm? Perimeter of new rectangle = 2(l2 + b2)= 2(24 + 10) = 2 x 34 = 68 cm
Area Problems Area of a square is 1/2 hectare. The diagonal of the square is? 50 meter 50? 2 meter 250 meter 100 meter 50 meter 50? 2 meter 250 meter 100 meter ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area = 1/2 hectare = 10000 / 2 m2= 5000 m2Again Area = 1/2 x (Diagonal)2So 1/2 x (Diagonal)2 = 5000m2? Diagonal2= 10000 ? Diagonal = 100
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