Area Problems A circle and a square have same area. The ratio of the side of the square and the radius of the circle is? ? : 1 1 : ? ?? : 1 1 : ?? ? : 1 1 : ? ?? : 1 1 : ?? ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? Area of square = Area of circle ? x2 = ?r2? x/r = ?? = ? ? : 1
Area Problems One side of a parallelogram is 8.06 cm and its perpendicular distance from opposite side is 2.08 cm. What is the approximate area of the parallelogram? 16.76 cm2 14.56 cm2 12.56 cm2 22.56 cm2 16.76 cm2 14.56 cm2 12.56 cm2 22.56 cm2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of parallelogram = Base x Height = 8.06 x 2.08 = 16.76 cm2
Area Problems If the radius of a circle is decreased by 50% , find the percentage decrease in its area. 75% 65% 25% 35% 75% 65% 25% 35% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP let original radius = r and new radius = (50/100) r = r/2 original area = ?r 2 and new area = ? r / 2 2 decrease in area = 3 ?r 2 / 4 * 1 ?r 2 *100 = 75%
Area Problems Angles of a quadrilateral are in the ratio 3 : 4 : 5 : 8. The smallest angle is 18° 36° 40° 54° 18° 36° 40° 54° ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let First angle = 3kSecond angle = 4kThird angle = 5k and Fourth angle = 8kWe know 3k + 4k + 5k + 8k = 360°? 20k = 360° ? k = 18 °Measure of smallest angle = 3k =3 x 18 ° = 54 °
Area Problems The area of circle inscribed in an equilateral triangle is 462 cm . The perimeter of the triangle is? 168 cms 126 cms 42 ? 3 cms 72.6 cms 168 cms 126 cms 42 ? 3 cms 72.6 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 circle of radius 21 cm an arc subtends an angle of 72° at the centre. The length of the arc is? 26.4 cm 19.8 cm 21.6 cm 13.2 cm 26.4 cm 19.8 cm 21.6 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
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