Question

What will be the change in the area of a rectangle if its

(i) Length and breadth are both doubled? 

(ii) Length is tripled and breadth is doubled twice?

Answer 1

(i) Let, length of rectangle = a and breadth = b 

Then, area = a × b = ab 

New length of rectangle = 2a and new breadth = 2b 

Then new area = 2a × 2b = 4ab 

= 4 × (ab) = 4 (initial area) 

Thus, area of rectangle became 4 times of initial area. 

(ii) Let, length of rectangle = a, and breadth = b 

Then, area = a × b = ab 

New length of rectangle = 3a and new breadth = 45 

Then New area = 3a × 4b 

= 12 ab = 12 (ab) = 12 (initial area) 

Thus, area of rectangle became 12 times of initial area.