Assume O₁ is at the origin and the O-C bond lies along the positive X-axis. From this, the coordinates of

O₁ are (0.0, 0.0, 0.0) and C₂ are (1.35, 0.0, 0.0).

To get the coordinates of H₃ and O₄, we have to use some trigonometry and recognize the 2 right triangles in the cis molecule.

Don't forget to make the appropriate modifications to (X3,Y3) and (X4,Y4). You have to add (or subtract accordingly) the coordinates of Atom 1 and Atom 2 to (X3,Y3) and (X4,Y4), respectively!

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