Talk:Tangent Points of Incircle in Terms of Semiperimeter

I took this proof (almost) verbatim from Inradius in Terms of Circumradius/Proof because I need it for work with excircles. Hope this is OK. --Telliott99 (talk) 13:35, 16 October 2023 (UTC)

You're asking what is $s$ in the text $s - a$, when it was defined in the line previous. Should I repeat the definition here? --Telliott99 (talk) 18:01, 16 October 2023 (UTC)