Area Problems The area of sector of a circle of radius 5 cm, formed by an arc of length 3.5 cm is? 35 sq.cms 17.5 sq.cms 8. 75 sq.cms 55 sq.cms 35 sq.cms 17.5 sq.cms 8. 75 sq.cms 55 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 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 if the side of a square be increased by 4 cms. The area increased by 60 sq. cms . The side of the square is? None of these 12 cm 13 cm 14cm None of these 12 cm 13 cm 14cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let each side = x cmThen, (x + 4 )2 - x2 = 60? x 2 + 8x + 16 - x2 = 60? x = 5.5 cm
Area Problems The area of circle inscribed in an equilateral triangle is 462 cm . The perimeter of the triangle is? 168 cms 72.6 cms 126 cms 42 ? 3 cms 168 cms 72.6 cms 126 cms 42 ? 3 cms ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 22/7 x r2 = 462? r2 = (462 x 7) /22 = 147? r = 7?3 cm ? Height of the triangle = 3r = 21?3 cmNow, ? a2 = a2/4 + (3r)2? 3a2/4 = (21?3)2? a2 = (1323 x 4)/3? a = 21x 2 = 42 cm? Perimeter = 3a = 3 x 42=126 cm
Area Problems In a rhombus, whose area is 144 sq.cmone of its diagonal is twice as long as the other, The lengths of its diagonals are? 12 cm, 24 cm 24 cm, 48 cm 6 ?2 cm, 12?2 cm 6 cm, 12 cm 12 cm, 24 cm 24 cm, 48 cm 6 ?2 cm, 12?2 cm 6 cm, 12 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of rhombus = (d1 x d2) / 2? (d x 2d ) / 2 = 144? d2 = 144? d = 12 ? Length of diagonal = 12 cm, 24 cm
Area Problems The length of a rectangle is double while its breadth is halved. What is the percentage change in area? None of these No change 75 50 None of these No change 75 50 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let length = l and breadth = bThen, area = lb New length = 2lAnd new breadth = b/2 ? New area = ( 2l ) x (b/2) = lbSo, there is no change in area .