I think that is A Because u multiplique
The area of the triangle will then be 9 times as great.
The formula of the area of a triangle is 1/2bh, so if the base has been tripled and the height has been tripled, you're essentially multiplying 3 to the original equation twice (3 x 3 = 9).
Yes you need to! And you need to be careful not to forgot that when doing your calculations!!