Area Problems
A circular wire of radius 42 cm is cut and bent in the form of a rectangle whose sides are in the ratio of 6: 5 . The smaller side of the rectangle is?
Perimeter of rectangle = Circumference of circle = 2?r=2 x ( 22/7 ) x 42= 264 cm Now perimeter of rectangle = 2 x ( 6a + 5a )? 2 x (6a + 5a) = 264? a = 12Smaller side of rectangle = 5a = 60 cm
Let original length = x and original breadth = y. Decrease in area = xy - ❨ 80 x x 90 y ❩ 100 100 = ❨ xy - 18 xy ❩ 25 = 7 xy. 25 ∴ Decrease % = ❨ 7 xy x 1 x 100 ❩% = 28%
AB = 60 m, BC = 40 m and AC = 80 m ? s = (60 + 40 + 80 ) / 2 m = 90 m (s-a) = 90 - 60 = 30 m, (s-b) = 90 - 40 = 50 m and (s-c) = 90 - 80 = 10 m? Area of ? ABC = ?s(s-a)(s-b)(s-c) = ?90 x 30 x 50 x 10 m2= 300?15 m2? Area of parallelogram ABCD = 2 x area of ? ABC = 600?15 m2
Area of the room =(544 x 374) cm2size of largest square tile = H.C.F. of 544 & 374 = 34 cm Area of 1 tile = (34 x 34) cm2? Least number of tiles required = (544 x 374) / (34 x 34) = 176
EXAMIANS