Javascript - Generalize a function that can be used in two different ways but in the same context

CODE

I have implemented a function that "responsify" dimensions (responsive dimensions).

This is my current method:

export default (originalDimensions, finalWidth = WINDOW_WIDTH) => {
  const responsiveWidth = finalWidth;

  const responsiveHeight = ruleOfThree(
    originalDimensions.height,
    originalDimensions.width,
    responsiveWidth
  );

  return {
    width: responsiveWidth,
    height: responsiveHeight,
  };
};

/* Helper */

function ruleOfThree (originalX, originalY, finalY, direct = true) => {
  if (direct) {
    return (originalX * finalY) / originalY;
  }

  return (originalY * finalY) / originalX;
};

Problem

As you can see, it just returns an object with responsive dimensions. The main problem I am experiencing is that it only adapts the given dimensions to a given "finalWidth". But what if, instead of a finalWidth, I receive a final height (so that the method adapts the original width to that final height)?

How can I add flexibility to the method in order to be able to solve that scenario without having to create another different method?

Any design pattern or idea?

Note

If I pass the final height (instead of a final width) as follows: responsifyDimensions(photo.dimensions, /*finalHeight = 100*/)

then, the method will have to do:

export default (originalDimensions, finalHeight = WINDOW_HEIGHT) => {
  const responsiveHeight = finalHeight; <----

  const responsiveWidth = ruleOfThree(
    originalDimensions.width,
    originalDimensions.height, <-----
    responsiveHeight <-----
  );

  return {
    width: responsiveWidth,
    height: responsiveHeight,
  };
}

Codes look really similar... so I suppose that there could be a simple way to make the original method more "flexible"