Igot these two questions wrong on my end of lesson assessment, i don't know how i got the wrong answer, i thought i used the correct formulas and all, could anyone walk me through how to get the correct answers?

Both those questions are the same, but with different choices.

Anyway, a triangle with sides 3, 4, and 5 is a right angled triangle with sides of 3 and 4, and 5 is the diagonal.
So its area = half x 3 x 4 = 6sq in

Volume = base x height  = 6 x 7 = 42 cubic in