The supercontinent was around how many years ago?

Pangea (the supercontinent) existed about 300,000,000 (Three hundred million) years ago.

The supermarket was around 335 million years.

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