Question

In each triangle in the diagram, the measurements that are labeled are known, while the other measurements are unknown. In which triangle can you directly substitute known values into the Law of Cosines to find an unknown side or angle?
@jagr2713

Answer 1

@sleepyjess @Compassionate @triciaal
sorry busy atm

Answer 2

oh oh oh Law of Cosines! I'm good at this, but I don't really understand the labels :/

Answer 3

But if you understand the labels, to use the Law of Cosines for an angle, you must know all 3 sides.

Answer 4

for the first one you can use the sine rule

Answer 5

use cosine rule for the 4th one

Answer 6

i reckon the other two are unsolvable

Answer 7

2nd one is sine rule

Answer 8

so 3 and 5 no go

Answer 9

Wait lol what?? @alekos @sleepyjess I'm mad confused now

Answer 10

I am really not sure what they have labeled...

Answer 11

The choices are
A) ABC
B) DEF
C) XYZ
D) PQR
E) JKL

Answer 12

Just so you know lol
@sleepyjess

Answer 13

@jagr2713 @alekos @jim_thompson5910

Answer 14

@TheSmartOne

Answer 15

Everything that is circled is what they have given: http://prntscr.com/62frx9 . Which of those triangles has all 3 sides circled?

Answer 16

4 out of the 5 @sleepyjess

Answer 17

Yep

Answer 18

So that is the only one where we can use the law of cosines right off the bat

Answer 19

And I take it thats the answer then? lol @sleepyjess

Answer 20

what so whats the answer? @sleepyjess

Answer 21

@yogi98 , I would be happy to help you when you come back online :)

Answer 22

@peachpi same picture used here