

Let the breadth be x.
Then, Length (l) = (x + 100) m and Diagonal (d) = (x + 200) m
(i)The diagonal of a rectangle divided it into two equal parts, so area of both the parts is same, also dimensions of both the triangles are same, so area will be same.
( ii )The shortest side is breadth i.e., x.
Now, to find shortest side i.e., breadth, we will use Pythagoras theorem:
(x + 200)2 = x2 + (x + 100)2
⇒ x2 + 40000 + 400 x = x2 + x2 + 10000 + 200x using (a + b)2 = a2 + b2 + 2ab
⇒ x2 + 40000 + 400 x = 2x2 + 10000 + 200x
⇒ 2x2 + 10000 + 200x - x2 - 40000 - 400 x = 0
⇒ x2 – 30000 – 200x = 0
⇒ x2 – 200 x – 30000 = 0
⇒ x2 – (300 – 100) x – 30000 = 0
⇒ x2 – 300 x + 100x – 30000 = 0
⇒ x (x – 300) + 100 (x – 300) = 0
⇒ (x – 300) (x + 100) = 0
⇒ x + 100 = 0
⇒ x = -100, which is not possible.
⇒ x – 300 = 0
⇒ x = 300 m
∴ The shortest side i.e., breadth is 300 m.
(iii) Breadth = 300 m
Length = (x + 100) m = (300 + 100) m = 400 m
Ratio of length and breadth:
=
=
= 4 : 3
