CBSE Class 9 Answered

Different countries use different poverty lines because  

i. The calorie which is required for different people is different based on their physical condition. For example, if a person is too tall and healthy would require more calories than the short person.  

ii. The per capita income in different countries is different. For example, per capita income is higher in developed countries than the developing countries.  

iii. The standard of living of Western countries is more than developing countries.  The cost of essential items used in calculating poverty line is more in the developed countries.