Find the area of triangle whose adjacent sides are 2i - 3j +5k, -i + 4j + 2k
Let vector a = 2i - 3j + 5k, vector b = -i + 4j + 2k
= i(-6-20) - j(4+5) + k(8-3)
= -26i -9j +5k
area = 1/2| vector a * vector b|
= 1/2√[(26)2 + (9)2 + (5)2]
= 1/2√(676 + 81 + 25)
= 1/2√782 sq.unit