Term
postulate 7
1st assumption |
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Definition
| if you have the set of all rays in a half plane, with a common vertex in the edge of the half plane, then, those rays can be put in a one to one correspondence with all of the real numbers from 0 to 180, inclusive in an ordered way, such that, either ray in teh edge of the half plane can be paired with zero |
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Term
postulate 7
2nd assumption |
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Definition
| if you have a pair of rays with a common end point in the edge of a hlaf plane then there corresponds to that pair of rays, exactly one number, called the unique measure of the angle formed by the rays |
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Term
postulate 7
3rd assumption |
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Definition
| if you have a pair of rays with a common end point in the edge of a half plane both of which have had coordinates assigned, then, the measure of the angle formed by those rays is the absolute value of the difference between those coordinates |
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Term
postulate 7
4th assumption |
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Definition
| if, in a half plane, a ray OB lies between rays OA and OC then the measure of angle AOB plus the measure fo angle BOC is equal to the measure of angle AOC. called the angle addition assumption |
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Term
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Definition
| the protractor postulate can be summarized briefly as follows to measure an angle you must attach numbers to the rays and find the unique measure fo that angle by taking the absolute value of the difference between the two coordinates |
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