Area Problems If the length of diagonal AC of a square ABCD is 5.2 cm then area of the square ABCD is? 12.62 sq.cm 15.12 sq.cm 10 sq.cm 13.52 sq.cm 12.62 sq.cm 15.12 sq.cm 10 sq.cm 13.52 sq.cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area = 1/2 x (Diagonal)2= (1/2) x 5.2 x 5.2 cm2= 13.52 cm2
Area Problems An error 2% in excess is made while measuring the side of a square. The percentage of error in the calculated area of the square is: 2.02% 4.04% 4% 2% 2.02% 4.04% 4% 2% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 100 cm is read as 102 cm. ∴ A1 = (100 x 100) cm2 and A2 (102 x 102) cm2. (A2 - A1) = [(102)2 - (100)2] = (102 + 100) x (102 - 100) = 404 cm2. ∴ Percentage error = ❨ 404 x 100 ❩% = 4.04%
Area Problems What is the area of a square having perimeter 68 cm? 289 sq cm 269 sq cm 361 sq cm 284 sq cm 289 sq cm 269 sq cm 361 sq cm 284 sq cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the question,4a = 68 [ where a = side]?a = 68/4 = 17 cm? Required area = a2= (17)2 = 289 sq cm
Area Problems If the radius of a circle is increased by 6%, find the percentage increase in its area. 8.39% 17% 12.36% 15% 8.39% 17% 12.36% 15% 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 If the sides of a rectangle are increased by 5%, find the percentage increase in its diagonals. 4% 6% 9% 5% 4% 6% 9% 5% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the formula,Percentage increase in diagonals = 5%
Area Problems A rectangle has 30 cm as its length and 720 sq cm as its area. Its area is increased to 1 1/ 4 times its original area by increasing only its length. Its new perimeter is 123 cm 119 cm 125 cm 121 cm 123 cm 119 cm 125 cm 121 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Original breadth of rectangle = 720/30 = 24 cmNow , area of rectangle = (5/4) x 720 = 900 cm2? New length of rectangle = 900/24 = 37.5 cm? New perimeter of rectangle = 2(l+ b)= 2(37.5 + 24 ) = 2 x 61.5 = 123 cm
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