End-to-end encryption and privacy controls.
Message and call for free* around the world.
Group conversations made simple.
Say it with stickers, voice, GIFs and more.
Reach your customers from anywhere.
http://sciences.farafile.ir/file/37386/ریاضی-دهم-فصل-دوم-(مثلثات)-با-زبان-ساده-و-نمایش-پویا--بخش-اول