Question

The area of the triangle formed the points (1, 1), (2, 2) and (-1, 2) is ​

Answer 1

Answer:

AB

=(1,1,−2)

AC

=(2,−1,−1)

n

=

AB

×

AC

=

∣

∣

∣

∣

∣

∣

∣

∣

i

^

1

2

j

^

1

−1

k

^

−2

−1

∣

∣

∣

∣

∣

∣

∣

∣

=−3

i

^

−3

j

^

−3

k

^

Area of Δ=

2

1

∣

n

∣

=

2

3

3