Question

36 unit squares are joined to form to form a rectangle with the least perimeter. Find perimeter of the rectangle.

• A. 12 units
• B. 26 units
• C. 24 units
• D. 36 units

Answer 1

The correct option is B 26 units

According to the question, 36 squares of unit length is joined together to form a rectangle.
The perimeter needs to be least, so we need to factorise 36.The prime factor of $36=2\times 2\times 3\times 3$
The possible dimensions of rectangle are (18, 2), (9, 4), (6, 6)
So, we take rectangle of dimensions 9cm by 4 cm in order to get least perimeter.
Hence, the perimeter =$2(l\times b)$
= 2 (9 + 4)
= 26 units