It presents some nice ideas, in my opinion, to solve types of really difficult problems in angle calculus, all full of thorns.Cuprins1 Useful theorems / lemmas2 New idea, two problems, one solution3 Incenter, circumcenter, excenter4 Mustafa Yagci triangle5 Triple angle lemma, double angle lemma6 Lemma, important7 Pantalon ` theorem, isogonal conjugate points8 Langley triangle properties9 Case of triangles congruency10 Various methods to solve problems11 Problems to be solved...