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 diagonal of a rectangle is 17cm long and its perimeter is 46 cm. Find the area of the rectangle. 130 140 120 110 130 140 120 110 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP let length = x and breadth = y then 2(x+y) = 46 => x+y = 23 x²+y² = 17² = 289 now (x+y)² = 23² => x²+y²+2xy= 529 => 289+ 2xy = 529 => xy = 120 area = xy = 120 sq.cm
Area Problems The area of the largest circle that can be drawn inside a rectangle with sides 18cm by 14cm is 154 49 1078 378 154 49 1078 378 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The diameter is equal to the shortest side of the rectangle. So radius= 14/2 = 7cm. Therefore, area of circle = (r)2 = (22/7) x 49 = 154 cm2
Area Problems The diagonals of two squares are in the ratio of 3 : 2. Find the ratio of their areas. 9 : 2 9 : 5 9 : 4 9 : 7 9 : 2 9 : 5 9 : 4 9 : 7 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the diagonals of the squares be 3x and 2x.? Ratio of their areas = [(1/2) (3x2)] / [(1/2) (2x2)] = 9/4
Area Problems A circular piece of thin wire is converted into a rhombus of side 11 cm. Find the diameter of the circular piece? 7 cm 3.5 cm 14 cm 28 cm 7 cm 3.5 cm 14 cm 28 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Circular piece is 4 x 11 = 44 cm long, Then Circumference of circle is given by, 44 = pi x D, where D is the diameter D = 44 / pi Take pi = 22 / 7, then D = 44 / (22/7) = (44 x 7) / 22 D = 14 cm.
Area Problems The diagonal of the floor of a rectangular closet is 7½ feet. The shorter side of the closet is 4½ feet. What is the area of the closet in square feet? 37 5(1/4) 13(1/2) 27 37 5(1/4) 13(1/2) 27 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Other side = (15 / 2) 2 - (9 / 2) 2 ft = (225 / 4) - (81 / 4) ft = 144 / 4 ft = 6 ft Area of closet = (6 x 4.5) sq. ft = 27 sq. ft.
EXAMIANS