Area Problems The area of sector of a circle of radius 5 cm, formed by an arc of length 3.5 cm is? 55 sq.cms 8. 75 sq.cms 35 sq.cms 17.5 sq.cms 55 sq.cms 8. 75 sq.cms 35 sq.cms 17.5 sq.cms ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of sector = ( arc length x radius ) / 2 cm2= (3.5 x 5 ) / 2= 8.75 cm2
Area Problems The base of right-angled triangle is 5 meters and hypotenuse is 13 meters . Its area will be? 28 m2 25m2 None of these 30m2 28 m2 25m2 None of these 30m2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Altitude = ?(13)2 - (5)2= ?144 = 12m ? Area of the triangle = (5 x 12 ) / 2 m2= 30m2
Area Problems The circumference of a circle is 25 cm. Find the side of the square incribed in the circle. 23/??2 25/??2 cm 29/??3 cm 21/??3 cm 23/??2 25/??2 cm 29/??3 cm 21/??3 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circumference of the circle = 2?r = 25? r = 25 / (2?)According to the formula,Side of inscribed square = r?2 = 25 / (2?r x ?2) = 25 / (??2 ) cm
Area Problems If the base of a rectangular is increased by 10% and the area is unchanged , then the corresponding altitude must to be decreased by? 10% 111/9 % 11% 91/11 % 10% 111/9 % 11% 91/11 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let base = b and altitude = h Then, Area = b x h But New base = 110b / 100 = 11b / 10Let New altitude = HThen, Decrese = (h - 10h /11 )= h / 11? Required decrease per cent = (h/11) x (1 / h ) x 100 %= 91/11 %
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? 21.6 cm 26.4 cm 13.2 cm 19.8 cm 21.6 cm 26.4 cm 13.2 cm 19.8 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 The ratio of the radii of two circle is 1:3 the radio of their areas is? 1:3 None of these 1:9 1:6 1:3 None of these 1:9 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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