Confusions....similar diagrams but diferent logic provided

[OCDS]

Okay. So this is from Flashcards G11 quiz…Q13

Here the logic was that B is greater as the tangent makes a 90 degrees angle, while the angle made by the chord will be less than 90

And this one is from the geometry foundation Quiz 1. Q10

Here it is mentioned that the second angle formed by the chord is 90.

How are there two different explanations for these two questions? or am I missing something?

[cylverixxx]

@OCDS

Here the logic was that B is greater as the tangent makes a 90 degrees angle, while the angle made by the chord will be less than 90

Let the secant line intersect the circle at two points: A and B. In that case, \triangle APB is an isosceles triangle, so it should be obvious now that \angle x < 90^{\circ} bc otherwise the central angle would be \leq 0.

@OCDS

Here it is mentioned that the second angle formed by the chord is 90.

This question isn’t related because this is just a special case of inscribed angle theorem. Owing to that, you get that \angle C = 90^{\circ}.

[OCDS]

Thanks/ i do understand these are not related diagrams. it’s just that i find it really confusing…as they look similar to someone like me whose Quant skills are dismal