Area Problems If the diagonal of a square is double, how does the area of the square change? Becomes two fold Becomes four fold None of these Becomes three fold Becomes two fold Becomes four fold None of these Becomes three fold ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of the areas = area of original square / area of new square = [ d2 / 2 ] / [ (2d)2 / 2 ] = 1/4? New area becomes 4 fold.
Area Problems A park of 10 meters long and 8 meters broad. What is the length of the longest pole that can be placed in the park? 10 metres 13.4 metres 12.8 metres 18 metres 10 metres 13.4 metres 12.8 metres 18 metres ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Length of the longest pole = ? [(10)2 + (8)2] m = ? 164 m = 12.8 m
Area Problems A triangle with three equal sides has its area equal to 3?3 sq cm . Find its perimeter . 2?3 cm 7?3 cm 5?3 cm 6?3 cm 2?3 cm 7?3 cm 5?3 cm 6?3 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the question,?3a2/4 = 3?3 [ side = a, and area = ?3a2/4] ? a2/4 = 3 ? a2 = 3 x 4 ? a = 2?3? Required perimeter = 3a =3 x 2?3 = 6?3 cm
Area Problems The area of the largest circle that can be drawn inside a rectangle with sides 18cm by 14cm is 49 1078 378 154 49 1078 378 154 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 radius of a circle is so increased that its circumference increased by 5%. The area of the circle, then increases by 11.25% 12.5% 10.25% 10.5 % 11.25% 12.5% 10.25% 10.5 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Increase in circumference of circle = 5%? Increase in radius is also 5%.Now, increase in area of circle = 2a + (a2/100) %Where, a = increase in radius= 2 x 5 + (5 x 5)/100 % = 10.25%
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? 4 cm 7 cm 5 cm 6 cm 4 cm 7 cm 5 cm 6 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
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