Let original length = x and original breadth = y. Original area = xy. New length = x . 2 New breadth = 3y. New area = ❨ x x 3y ❩ = 3 xy. 2 2 ∴ Increase % = ❨ 1 xy x 1 x 100 ❩% = 50%
Let original radius be r.Then, according to the questions,? (r + 1)2 - ?r2 = 22? ? x [(r + 1)2 - r2] = 22? (22/7) x (r + 1 + r ) x (r + 1 - r) = 22? 2r + 1 = 7 ? 2r = 6 ? r = 6/2 = 3 cm
Given that, a = 8 cm, b = 10 cm and c = 12 cm We know, that s = (a + b + c)/2 = (8 + 10 + 12)/2= 30/2 = 15 cm ? (s - a) = (15 - 8) = 7 cm (s - b) = (15 - 10) = 5 cm (s - c) = (15 - 12) = 3 cm ? Area = ?s(s - a) (s - b) (s - c)= ?15 x 7 x 5 x 3= ?1575= ?25 x 63= 5?63 cm
EXAMIANS