Video: 5iYQCdL-bz4

Apuntes

• Introduction [Music] welcome to mass with WL today we're looking at non right angle triangle trigonometry uh the two rules basically the sign Rule and the cosine rule you might remember right angle triangle trigonometry was the sakar idea uh today we're just uh going to go over the sign Rule and the cosine rule with a few examples okay so the first thing is obviously the triangle is non right angled just start with obviously and let's have a look so first up uh a couple of ideas a I'm going to put a b and c okay and you can see here the that would be angle a up here and opposite it uh over here would be side a okay so opposite angle a is side little a so we have these big letters and little letters okay let's have a look at uh uh okay obviously C is over here and opposite it it would be a uh little C okay here's a little C and again obviously opposite B would be a little B so okay we have angles with marked as capital letters inides lowercase letters okay so basically the sign rule is a over s of its angle is equal to B on the sign of its angle and which is also equal the C over the sin of C but we only normally set up proportion equations and we only have normally using two so ...