Editorial archive · Filtered view
Tag: Bmo1 Geometry
All BMO and UKMT Pathway Guide editorial articles matching this filter. Browse the full archive at News & Updates, or use the navigation to filter by stage, paper, or topic tag.
-
BMO1 angle chasing: a configuration audit before you add an auxiliary circle
Before adding an auxiliary circle in a BMO1 angle chase, record which side of each chord the key points lie on, the order of points on each line, and whether the quadrilateral is convex or crossed. Equal angles alone are not enough: same-side equal angles support concyclicity; opposite-side equal angles generally do not. Read article
-
BMO Trigonometry: When a Geometry Proof Needs Sine Rule Before an Auxiliary Line
For BMO geometry proofs involving side ratios in adjacent triangles, apply the sine rule before adding auxiliary lines. This guide explains when to use metric trigonometry versus circle or line constructions. Read article
-
BMO Geometry Auxiliary Construction: Choosing Between Circle and Line
Stuck on a BMO1 geometry proof? Learn when to introduce an auxiliary circle for angle chasing versus an auxiliary line for ratios and similarity. Read article
-
BMO1 Geometry Decoded: The Configurations, Tools and Write-Up Habits That Earn Marks
Recognise the configuration, choose the right tool, then write it so a marker can follow: a practical geometry guide for the six-problem BMO1 paper. Read article