This continent is the second-largest. It is widely regarded as the birthplace of man because the oldest human bones on record have been found there.

Africa

Explanation:

After Asia, which is the largest continent of the world, Africa comes second in terms of land area and also by population. Africa has a land area of about 11,724,000 square miles (30,365,000 square km), which accounts for about one-fifth of the total land area on earth. Africa is also the second largest continent on earth by population size, with an estimated total human population of approximately 1.3 billion people.

Africa is nicknamed "mother continent" as it is said to have been where man have first lived in and originated from, according to archaeological discoveries and facts which dates back to more than 2 million years ago.

the answer would be the third option, "no, ariel should have added 9^2 and 12^2 and compared that to 15^2."

this is found through the pythagorean theorem, which is a^2 + b^2 = c^2.

this is the correct way of solving the problem:

9^2 + 12^2 = 15^2

81 + 144 = 225

225 = 225