A student writes: “In △ABC and △PQR, AB=PQ, BC=QR and ∠A=∠P. Therefore the triangles are congruent by SAS.” Which statement best explains the error in this reasoning?
(a) SAS is valid only for right-angled triangles, which are not specified here.
(b) SAS cannot be applied because it actually demands three pairs of equal sides, not just two.
(c) The angle cited is not the one included between the two equal sides, so the SAS criterion does not apply.
(d) The equal angle should lie opposite the equal sides for SAS; since it doesn’t, the triangles need not be congruent.