Question

The vertices of a ΔABC and given by A(2, 3) and B(–2, 1) and its centroid is G Find the coordinates of the third vertex C of the ΔABC.


A. (0,2)
B. (1,-2)
C. (2,-3)
D. (-2,3)

​

Answer 1

Answer:

Let A(3,2),B(−2,1) and C(x,y) be the coordintes of a triangle.

Centroid(

2

5

,

3

−1

)=(

3

3−2+x

,

3

2+1+y

)

Equating the x−co-ordiantes and y−co-ordinates we get

3

1+x

=

2

5

2+2x=15

or x=

2

13

And

3

3+y

=

3

−1

y+3=−1 or y=−4

∴ the coordinate C is (

2

13

,−4)