Question Number 88301 by byaw last updated on 09/Apr/20
$${A}\:{circle}\:{touches}\:{the}\:{four}\:{sides} \\ $$$${of}\:{quadrilateral}\:{ABCD}.\:\mathrm{Show}/\mathrm{prove} \\ $$$$\mathrm{that}\:\mathrm{A}{B}+{CD}={BC}+{DA}. \\ $$$$\mathrm{Please}\:\mathrm{help}. \\ $$
Commented by mr W last updated on 09/Apr/20
Commented by mr W last updated on 10/Apr/20
$${AB}+{CD}={AE}+{EB}+{DG}+{GC} \\ $$$$={AH}+{BF}+{HD}+{FC} \\ $$$$={AH}+{HD}+{BF}+{FC} \\ $$$$={AD}+{BC} \\ $$$$={BC}+{DA} \\ $$