The Mohr-Mascheroni theorem says anything constructible with ruler and compass can be built with what alone?
- A protractor
- A ruler
- A set square
- A compass
Show answer and solution
Correct answer: D. A compass
1. The theorem covers constructions where data and results are discrete points.
2. In that case the compass alone is enough.
3. A ruler alone cannot find a midpoint or take a square root.
_Source: Wikipedia, Straightedge and compass construction, section Constructing with only ruler or only compass_