I mean, the assumption shouldn’t be anything about scale. It should be that we’re looking at straight lines. And if we can’t assume that, then what are we even doing.
But, assuming straight lines, given straight lines you find the other side of an intersecting line because of complements.
And if we can’t assume that, then what are we even doing
That’s exactly what the other user is saying. We can’t assume straight lines because the given angles don’t make any sense and thus this graph is literally impossible to make. We’re arguing over literal click bait is what we’re doing.
Because the angles aren’t represented accurately. It could be that the two angles that look like they’re 90° add up to 180°, but they could also not
We can’t assume that the straight line across the bottom is a straight line because the angles in the drawing are not to scale. Who’s to say that the “right angle” of the right side triangle isn’t 144°?
If the scale is not consistent with euclidian planar geometry, one could argue that the scale is consistent within itself, thus the right triangle’s “right angle” might also be 80°, which is not a supplement to the known 80° angle.