Please help me with this! What type of weathering is happening in the picture?

Erosion

Explanation:

Erosion occurs when wind, water, dirt, etc. tears away a surface. These bricks were eroded away, and as a result are bumpy and rigid.

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