Hi! This is more of a general question than a problem, but for anybody doing constructions in geometry(ex. Given an angle, construct a congruent angle) using compasses(and rulers, but mostly compasses) how do you make sure that you keep the center point of the compass/the whole ruler straight? I'm constantly having trouble with that as it keeps moving and bringing my results a degree or two away from the original angle degree value. Any suggestions would be greatly appreciated. Thanks!

The first one (color) is typical of the kind one might use in elementary school. It is possible that it could be bent, wedged, or clamped in such a way that its tendency to change radius would be substantially reduced. There are versions of this first type that have a screw clamp to hold the parts in place.

The second one is an engineering/drafting quality compass that has its radius set by a screw. It is much less likely to change radius "uncommanded." Unfortunately, the cost of such a precision instrument can be somewhat higher than for the dime-store type compass.

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Additional comment

In general, it is a good idea to invest in the best tools you can afford. It is possible that these will show up at a second-hand store or flea market for less than their original cost.