Licks, H. E · New York, D. Van Nostrand company · leaf 65
cle and their sum is hence equal to it. Accordingly, it has been proved that the semicircumference of any circle is equal to its diameter. Where lies the fallacy? 82 To prove that any obtuse angle is equal to a right angle. Let ABC be an obtuse angle and DCB a right angle; it is required to prove… … opposite the side GA is equal to the angle opposite the side GD. Accordingly the angle ABG equals the angle DCG; subtracting from these the equal angles CBG and BCG, the result is that the angle ABC is equal to the angle DCB. Therefore, it has been proved that the obtuse angle ABC is equal to the…
Mathematical recreations
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