Re: Calculate X in a circle

Quote:

Originally Posted by

**gingerale**

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Don't you know that

Why is that true?

Re: Calculate X in a circle

So the opposite angel is a reflection that together is equal to 180? X = 122, and the angel that is unmarked would then be 77, all together 360. Makes sense. Why is the circle there then, just for confusing? :)

Re: Calculate X in a circle

Re: Calculate X in a circle

Generally speaking it is true that the measure of an angle, with vertex on a circle, is **half** the angle measure of the arc it subtends. Here, the angle opposite x has measure 58 degrees and so subtends an arc of angle 116 degrees. Then entire circle has 360 degrees so that leaves 360- 116= 144 degrees for the arc subtended by angle x.