Question

So Anar also tried many different ways to make a boundary for 800 square meters of land.

He made rectangles A, B, and C of different sizes. Find out the length of the boundary of each. How much gold wire will he get for these rectangles?

• A 
  Gold wire for A = _________ metres
• B 
  Gold wire for B = _________ metres
• C  
  Gold wire for C = __________ metres

But then Anar made an even longer rectangle... See how long!

• D 
  So he will get __________ metres of gold wire!!

Answer 1

Area of 30 m × 20 m rectangle = 600 square metres

Its area is larger than the area of the first rectangle.

The other rectangles that he can make with 100 metres of wire are

40 m × 10 m,

48 m × 2 m,

49 m × 1 m,

45 m × 5 m

• A 
  As the area of a rectangle, A is shown as 40 m × 20 m.
  So, the length of rectangle = 40 m
  Width of rectangle = 20 m
  Gold wire for A
  =  40 + 20 + 40 + 20 
  =  120  metres
• B  
  As the area of rectangle B is shown as 80 m × 10 m.
  So, the length of rectangle = 80 m
  Width of rectangle = 10 m
  Gold wire for B
  =  80 + 10 + 80 + 10 
  =  180  metres
• C
  As the area of rectangle C is shown as 800 m × 1 m.
  So, the length of rectangle = 800 m
  Width of rectangle = 1 m
  Gold wire for C
  =  800 + 1 + 800 + 1 
  =  1602  metres
• D
  As the area of rectangle D is shown as 8000 m × 0.1 m.
  So, the length of rectangle = 8000 m
  Width of rectangle = 0.1 m
  Gold wire for C
  =  8000 + 0.1 + 8000 + 0.1 
  =  16000 + 0.2 
  =  16000.2  metres.

So, he will get 16000.2  metres of gold wire!!