| course | course_year | question_number | tags | title | year | |||
|---|---|---|---|---|---|---|---|---|
Geometry |
IB |
25 |
|
Paper 3, Section I, |
2016 |
(a) State Euler's formula for a triangulation of a sphere.
(b) A sphere is decomposed into hexagons and pentagons with precisely three edges at each vertex. Determine the number of pentagons.