Question 1
SEAMO self-study edition 2027; not an official 2027 paper. Original source years are retained. 25 questions, 90 minutes; Q1–10: 3 points, Q11–20: 4 points, Q21–25: 6 points, total 100. Original response types and all subparts are preserved. Verified is an editorial convention; source defects, necessary assumptions and unresolved mathematical uncertainty are disclosed.
Point $P$ lies inside equilateral triangle $ABC$. Given $\angle APB=120^\circ$ and $\angle BPC=130^\circ$, if segments $AP,BP,CP$ form the sides of a new triangle, what is its largest angle?
Point $P$ lies inside equilateral triangle $ABC$. Given $\angle APB=120^\circ$ and $\angle BPC=130^\circ$, if segments $AP,BP,CP$ form the sides of a new triangle, what is its largest angle?