Question

Help with getting some sides of a triangle in trig

Answer 1

i know A=25

Answer 2

I always use the sine rule, even when I'm meant to use trigonometry. I can't help you on the specific question that you're on, without a diagram though. If you post the question, I could show you how to use the sine rule to calculate the unknown side/angle.

Answer 3

Ahh, I see you've posted the question. Give me a minute.

Answer 4

The sine rule is that a side divided by the opposite side is equal to any other side divided by its opposite side. This applies to all triangles. To work out a:
\[10/\sin 30 = a /\sin 25\]
So then you can move the sin 25 onto the other side:
\[\left( 10/\sin 30 \right) \times \sin 25\]
Which would give you: 8.45236523482 for a.

Working out b:
\[\left( 10/\sin 30 \right) \times \sin 125\]
Answer: 16.38304088578

Answer 5

I get the sin25/a but why would we use sin30/10?

Answer 6

The sine rule states that any side divided by the sine of the opposite angle is equal to any other side divided by the sine of its opposite angle. Therefore, in order to work out anything using the sine rule, you need a known side and its opposite angle to be know too. We have that: \[10/\sin 30\]

Answer 7

10 is the known side and 30 is the known opposing angle.

Answer 8

Hold on a second please

Answer 9

Okay.

Answer 10

I think I understand it now

Answer 11

Well, I'm glad to be of help. If my answers answered your question, don't forget to select it as the best answer. See ya!