Area of a triangle using sine

How to calculate the area of a triangle using the sin function.

[@TehObLiVioUs]

nice thumbnail
got me clicking right away

[@kerimm.3712]

thanks

[@animeworld6730]

You used cos and not sine right?

[@aarushpruthi346]

Derivation?

[@holydoor]

my goofy geometry teacher had us watch this😡