Canon agonises somewhat to reveal figure

• Its internal angles total 1,260 degrees
• Defective stop sign?
• Figure a small number continue to badger
• A nine-sided polygon
• Shape with one more side than a stop sign
• Many-sided figure
• Figure of horse appearing in middle of day
• Drama introduces Harry: touching figure!

Wiktionary Word definitions in Wiktionary
n. (context geometry English) A polygon with nine sides and nine angles.