Area Problems The length of a rectangular field is 100 m and its breadth is 40 m. What will be the area of the field? (4 x 102) sq m (4 x 104) sq m (4 x 10) sq m (4 x 103) sq m (4 x 102) sq m (4 x 104) sq m (4 x 10) sq m (4 x 103) sq m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Required area = Length x Breadth= 100 x 40 = 4000 sq m= 4 x 103 sq m
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? 7 cm 6 cm 5 cm 4 cm 7 cm 6 cm 5 cm 4 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 What is the diameter of the circle having 3 cm radius? 8 cm 12 cm 1.5 cm 6 cm 8 cm 12 cm 1.5 cm 6 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Radius = Diameter/2 ? Diameter = 2 x Radius = 2 x 3 = 6 cm
Area Problems The sides of a triangular board are 13 meters, 14 meters and 15 meters. The cost of paining it at the rate of Rs. 8.75 per m 2 is? Rs. 722.50 Rs. 688.80 Rs. 730.80 Rs. 735 Rs. 722.50 Rs. 688.80 Rs. 730.80 Rs. 735 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP s = (13 + 14 + 15 ) / 2 = 21, s-a = 8 , s-b = 7, s-c= 6? Area to be painted = ? [s(s-a) (s-b) (s-c)]=? [21 x 8 x 7 x 6] m2= 84 m2? Cost of painting = Rs. (84 x 8.75) = Rs. 735
Area Problems The length of a room is 5.5 m and width is 3.75 m. Find the cost of paying the floor by slabs at the rate of Rs. 800 per sq.metre. Rs.18500 Rs.15500 Rs.17500 Rs.16500 Rs.18500 Rs.15500 Rs.17500 Rs.16500 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area = 5.5 × 3.75 sq. metre. Cost for 1 sq. metre. = Rs. 800 Hence total cost = 5.5 × 3.75 × 800 = 5.5 × 3000 = Rs. 16500
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: 4% 2.02% 4.04% 2% 4% 2.02% 4.04% 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%
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