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October 11

Geometry problem, acceptable solution?

In this problem: "given a circle with a diameter marked on it,j and a point on the circle, can you find a way to draw a line from the point that hits the diameter at a right angle." and considering the "restriction not to allow measuring devices, which means that you cannot use a compass or a marked ruler. All you are allowed is an unmarked ruler to draw straight lines."

For visualizing it: [1]

For the whole story: Guardian article with a link to a solution.

Would this also be a possible and acceptable solution:

draw tangents touching the three given points
mark the two points where the tangents of the points marked on the diameter intercept the tangent of the point on the circle.
connect these two points to the points marked on the diameter.
draw the line.

--Bumptump (talk) 17:16, 11 October 2021 (UTC)[reply]

@Bumptump: I'm afraid it's not acceptable. Classic constructions do not allow 'drawing a tangent'. A line can be drawn through any two known points. So you'd have to find (construct) another point on a tangent prior to drawing the line. --CiaPan (talk) 19:58, 11 October 2021 (UTC)[reply]