Here, `|z_1| = |z_2| = |z_3| = 1`
As `|z_1| = 1=>z_1.bar(z_1) = 1`
`bar(z_1) = 1/z_1`
Similarly, `bar(z_2) = 1/z_2`
`bar(z_3) = 1/z_3`.
We are given,
`|1/z_1+1/z_2+1/z_3| = 1`
`:. |bar(z_1)+bar(z_2)+bar(z_3)| = 1`
Also, we know,
`|z| = |barz|`
`:.|bar(bar(z_1)+bar(z_2)+bar(z_3))| = 1`
`:. |z_1+z_2+z_3| = 1`