section_heading: Dokaz
paragraph_text: \begin{align} & |\angle DCA| = |\angle DAC| \\[6pt] \Rightarrow {} & |AD| = |CD|, \text{ te } |\angle DIA| = 180^\circ - |\angle AIB| \\[6pt] = {} & 180^\circ - (180^\circ - |\angle IAB| - |\angle IBA|) \\[6pt] = {} & |\angle IAB| + |\angle IBA|= |\angle IAC| + |\angle CAD| \\[6pt] = {} & |\angle IAD| \\[6pt] \Rightarrow {} & |AD| = |DI|. \end{align} </math>