How to Calculate Gravitational Force in a Triangular Configuration?

[ravennnn]

3 10 kg spheres are located at the corners of a equilateral triangle of sides .5m. Calculate the magnitude of the total gravitational force exerted on one sphere by the other two.

I used G = 6.67 x 10^-11.
The answer I got was 4.62 x 10 ^-8. Can anyone confirm if this is correct, or explain how to get the correct answer?

 

[fzero]

It's much better if you explain how you got that answer. This way any mistakes can be pointed out.

 

[ravennnn]

Well I picked the ball in the bottom left corner, and found that the vector components of the force the ball to the right of it exerts on it is (2.668 x 10^-8, 0).

The force the top ball exerts on the bottom left corner would have vector components (2.668 * 10^-8cos(60), 2.668 * 10^-8sin(60)). I added these two vectors up, and got the resultant vector components, which I used the distance formula to find the magnitude and got 4.62 x 10 ^-8.

 

[ravennnn]

Can anyone confirm if I did it right, or point out any mistakes I made?

 

[fzero]

Looks good to me.