Olympiad Geometry for Year 9: Inversion, Tangents & Power of a Point | KidMathClub

Several recent lessons from AI Mohr beautifully overlap with topics we explore in our Year 9 groups - a great example of how classical olympiad geometry keeps reappearing across modern mathematical communities.

Recent topics included:

➤ Inscribed angles and their central “twins”

➤ Secants from an outside point - the Power of a Point theorem

➤ Constructing tangent lines from external points

➤ The Pappus Chain and inversion geometry

➤ Advanced inversion puzzle sets

What we especially love is that these topics are not taught as isolated formulas. Students learn to:

• recognise hidden structures,

• transform difficult configurations,

• use symmetry and inversion,

• and approach geometry as a creative investigation.

Many of these ideas appear later in:

• Olympiad geometry

• advanced UKMT work

• mathematical circles

• and university-level problem solving.

Geometry at this level stops being “school maths” and starts feeling like research.

Links for students who want to explore further:

📎 Inscribed angles - https://locuscanvas.com/notebook/2026-04-30

📎 Power of a Point - https://locuscanvas.com/notebook/2026-05-01

📎 Tangent constructions - https://locuscanvas.com/notebook/2026-05-02

📎 Pappus Chain & inversion - https://locuscanvas.com/notebook/2026-05-06

📎 Inversion puzzle set - https://locuscanvas.com/puzzles/inversion

Olympiad Geometry for Year 9: Inversion, Tangents & Power of a Point | KidMathClub