Geometrymedium · Past Paper
Angle sum of a triangle is 180. This is based on which postulate?
AEuclid's parallel postulate
BPythagoras postulate
CArchimedes principle
DThales postulate
✓ Correct Answer: A — Euclid's parallel postulate
The fact that triangle angles sum to 180 degrees is a direct consequence of Euclid's fifth (parallel) postulate.
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