Law of Cosines

**topaz192** · August 28th 2008, 05:44 PM

I dont know how to find the side!

Problem: a= 16 c= 12 B= 63degrees

I know the formula to use afterwards.

a^2=b^2 + c^2 - 2bc COS A

**Jhevon** · August 28th 2008, 05:58 PM

Originally Posted by topaz192

I dont know how to find the side!

Problem: a= 16 c= 12 B= 63degrees

I know the formula to use afterwards.

a^2=b^2 + c^2 - 2bc COS A

you're supposed to use the formula to find the side.

$b^2 = (16)^2 + (12)^2 - 2(16)(12) \cos 63$

use that to find the other side, b

**JOhkonut** · August 28th 2008, 05:58 PM

Originally Posted by topaz192

I dont know how to find the side!

Problem: a= 16 c= 12 B= 63degrees

I know the formula to use afterwards.

a^2=b^2 + c^2 - 2bc COS A

Try this version of the formula:
$<br /> b^2=a^2+c^2-2ac\cos B$
It's the exact same thing with the letters rearranged.

[EDIT]
Dang he beat me, lol.

**topaz192** · August 28th 2008, 06:12 PM

lol yea i found a tutorial online thanks for your time though!

Thread: Law of Cosines