उस प्राथमिक आधार की पहचान कीजिए जिसके आधार पर एक त्रिकोणीय प्रणाली (triangulation system) को प्रथम-श्रेणी, द्वितीय-श्रेणी और तृतीय-श्रेणी के त्रिकोणीयन में वर्गीकृत किया जाता है।

The 'Drain of Wealth' theory was propounded by which Indian nationalist leader?

Which event is considered the turning point in Mahatma Gandhi's leadership in the Indian independence movement?

Which African leader is known for his non-violent opposition to colonial rule?