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 6 cm 7 cm 4 cm 5 cm 6 cm 7 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 Find the area of a rectangle having 15m length and 8m breadth. 125 sq m 120 sq m 111 sq m 115 sq m 125 sq m 120 sq m 111 sq m 115 sq m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Required area = Length x Breadth= 15 x 8 = 120 sq m
Area Problems The length and breadth of a playground are 36 m and 21 m respectively. Flagstaffs are required to be fixed on all along the boundary at a distance of 3 m apart. The number of flagstaffs will be? 38 40 37 39 38 40 37 39 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Perimeter = 2 x (36 + 21 ) m = 144 m ? Number of flagstaffs = 144 / 3 = 38
Area Problems Area of a square with side x is equal to the area of a triangle with base x. The altitude of the triangle is? x/2 4x x 2x x/2 4x x 2x ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let h be the altitude of triangle.So area of triangle = (1/2)xh area of square = x2From question area of square = area of triangle x2 = (1/2)xh ? h = (2x2)/x = 2x
Area Problems If the radius of a circle is increased by 6%, find the percentage increase in its area. 15% 8.39% 17% 12.36% 15% 8.39% 17% 12.36% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Given that, a = 6 According to the formula,Percentage increase in area= 2a + [a2/100]%= 2 x 6 + [36/100]%= (12 + 0.36)%= 12.36%
Area Problems The ratio of the radii of two circle is 1:3 the radio of their areas is? 1:9 1:3 None of these 1:6 1:9 1:3 None of these 1:6 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The Radio of areas = area of first circle : area of 2nd circle= ?r2 / ?(3r)2= ?r2/ 9 ?r2= 1/9 = 1: 9
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