Question

Find the area of the triangle having 3i+4j and -5i+7j as two of its sides​

Answer 1

Answer:

Let vector a = 2i - 3j + 5k vector b = -i + 4j + 2k= i-6-20 - j4+5 + k8-3= -26i -9j +5karea = 1/2| vector a * vector b|= 1/2√[262 + 92 + 52]= 1/2√676 + 81 + 25= 1/2√782 sq.unit