Madaidaicin triangle shine siffar geometric mai kusurwa ɗaya mai auna digiri 90 ko kusurwar dama. Wannan triangle yana da gajerun gefuna guda biyu, waɗanda aka sani da ƙafafu, da kuma gefe mai tsayi kishiyar kusurwar dama, wanda ake kira hypotenuse. Ka'idar Pythagorean ita ce ka'ida ta asali na madaidaiciyar triangles, wanda ke nuna cewa murabba'in hypotenuse daidai yake da jimlar murabba'in ƙafafu. Madaidaitan triangles suna da mahimmanci a cikin lissafi, injiniyanci, da kimiyyar lissafi kuma suna da aikace-aikace masu amfani da yawa a cikin matsalolin duniya.