Find the area of the triangle with vertices A(1, 1, 2), B(2, 3, 5) and C(1, 5, 5) © NCERT
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VECTOR ALGEBRA
455
10 Find the area of the parallelogram whose adjacent sides are determined by the
vectors 
ˆ
ˆ
ˆ
3
a
i
j
k
=
−
+
r
and 
ˆ
ˆ
ˆ
2
7
b
i
j
k
=
−
+
r 11