| ‌‌=6(4+1)−3(−5)−4(−10) ‌‌=85 And OB×OC‌‌=|
1
5
k
0
2
1
5
−1
2
| ‌‌=5i+5j−10k Then the magnitude of above is |OB×OC|‌‌=√25+25+100 ‌‌=5√6 The height of the parallelopiped drawn from A is OA⋅(OB×OC)‌‌=‌