You can do part a using The Pythagoras theorem:-
30^2 = x^2 + 24^2
x^2 = 30^2 - 14^2 = (30+24)(30-24) = 324
x = 18
65 is the asnwer hope i helped
In order to find the volume of a triangular pyramid, you must use the formula (abh)/6. Therefore, I believe the answer is 12 (if [a = a] [b = h] and [c = b]).