Question

If two vertices of a triangle are (1, 1, 1).(-2, 4, 1) and the centroid is the origin then find the third
vertex​

Answer 1

Answer:

Let the △ABC has vertices A=(x

1

,y

1

)=(−1,4),B=(x

2

,y

2

)=(5,2) and C=(x

3

,y

3

).

The centroid G=(

3

x

1

+x

2

+x

3

,

3

y

1

+y

2

+y

3

)=(0,−3)

Therefore,

3

−1+5+x

3

=0

⇒x

3

=−4

Also

3

4+2+y

3

=−3

⇒y

3

=−15

∴C=(x

3

,y

3

)=(−4,−15)