So add all of them and then see smallest one sorry if I'm wrong
Let the second no. be x
-3x = 21 → x = 21/-3 → x = -7
Vol (pyr) = 1/3 b × h, where h = 15 and b = base = area of triangular base = 1/2 b×h, where h = 12 and b = 13
V = 1/3 (1/2×12×13)×15
V = (1/3×1/2×12)×13×15
V = 2×13×15 = 30×13 = 390 in^3
Exactly 10,000 it’s hard to explain though it’s really complicated
