00:01
So i have some information about a triangle, right? given any triangle, i have three angles, capital a, b, and c.
00:06
And then the sides across from the angles are the lower case versions of those angles.
00:11
Okay.
00:12
So i have angle a.
00:14
I have angle c.
00:15
If i have two angles, i can solve for a third, right? my third angle b would do all angles in a triangle at up to 180.
00:24
So i'm just going to subtract 180, minus 110, minus angle c, minus angle.
00:31
And that'll give me approximately 38 degrees exactly.
00:35
So angle b is 38 degrees.
00:39
I also know that side length b is 12.
00:42
What do i want to find next? well, since i have all my angles and only have one side length, when i have more angles than sidelines, i'm gonna use law of signs.
00:51
When i have more sides than angles, i'm gonna use law of cosine.
00:54
So i'm gonna find angle a or side length a.
00:58
For law of signs, i need the angle in the side across from each other.
01:02
So i'm going to do sign of a, 110 degrees over side length a equals.
01:08
I need another pair of angle in sidelines.
01:11
So i'm going to use b's sign of b, which is 38 degrees, all over side length of b, which is 12.
01:18
Okay.
01:19
Now that i set it up using the law of signs, i could cross multiply numerator of one fraction times the denominator of the other.
01:29
What's my goal when i set up this equation to get a by itself? so i'm going to divide by what i'm multiplying by when i move something to the other side, i do the opposite operation.
01:39
And then what i can do is just plug this all into my calculator...