Two triangles satisfy $AB=PQ$, $BC=QR$ and $\angle BAC=\angle QPR$. A pupil claims that SAS pr

Question

Two triangles satisfy $AB=PQ$, $BC=QR$ and $\angle BAC=\angle QPR$. A pupil claims that SAS proves $\triangle ABC\equiv\triangle PQR$. Explain why this use of SAS is invalid.[2] State an angle equality which, together with the two given side equalities, would allow SAS to be used.[1]

Accepted Answer

(a) The given angle is not between the given sides; SSA is insufficient in general. (b) $\angle ABC=\angle PQR$

Recognising insufficient information

Recognising insufficient information

Solution:

Solution locked