Area Problems
A rectangular carpet has an area of 60 sq. m. Its diagonal and longer side together equal 5 times the shorter side, The length of the carpet is?
Let the longer side = l, shorter side = b and diagonal = dThen, area of rectangular carpet = l x b = 60 ....(1) And from question d + l = 5b? d = 5b - l ...(2)? d2 = 25b2 + l2 - 10 x lb? l2+ b2 = 25b2 + l2 - 10 x lb? l2+b2 = 25b2 + l2 - 10 x 60? 24b2 = 600? b = ?25 = 5 m? l = 60 / b = 60 / 5 = 12 m
According to the question,l/[2(l + b)] = 5/18? 10l + 10b = 18l = 10b? l/b = 10/8 = 5/4? l : b = 5 : 4Hence, ratio of length and breadth of a rectangle is 5 : 4
Let length of the longer diagonal = d cmThen, length of other diagonal = 0.8 x d cm Area of rhombus = (1/2) x d x 0.8 x d = 2/5 d2= 2/5 d2Area of square of the length of the longer diagonal = d2So the area of the rhombus is 2/5 times the square of the length of the longer diagonal.
Let original length = x metres and original breadth = y metres. Original area = xy sq.m Increased length = 120 100 and Increased breadth = 120 100 New area = 120 100 x * 120 100 y = 36 25 x y m 2 The difference between the Original area and New area is: 36 25 x y - x y 11 25 x y Increase % = 11 25 x y x y * 100 = 44%
EXAMIANS