C-08-Q135mediumsingle_mcq
In the proof, is the second intersection point of side with the auxiliary circle through . We deduce , which contradicts—
In the proof, is the second intersection point of side with the auxiliary circle through . We deduce , which contradicts—
- athe angle sum of a triangle
- ban exterior angle being greater than the opposite interior angle
- cthe law of sines
- dthe law of cosines
ব্যাখ্যা
Because is an exterior angle of triangle , it must be greater than the opposite interior angle ; the equality contradicts this exterior-angle inequality, so the fourth vertex must lie on the circle.