i. 1 m = 100 cm
If one side is x cm, then the other side is 50 – x.
Area of rectangle = a(x) = x(50 – x)
= 50x – x2 cm2
a(x) = 50x – x2
ii. a(10) = 50 × 10 – 102 = 500 – 100 = 400
a(40) = 50 × 40 – 402 = 2000 – 1600 = 400
10 and 40 are the sides of rectangle, so a(10) and a(40) are same .
iii. Numbers must be sides of rectangle. If we add the two numbers together we get the sum as half the length of the wire (50 cm) used to make it.