Question

a = 5 and c = 20. Find A and round to two decimal places.

Answer 1

Is A equal to 14.48 degrees?

Answer 2

Are you familiar with the law of sines?

Answer 3

Yes, but I don't think they're needed here.

sinA = 5/20

A = sin^-1 * 5/20

Answer 4

It makes things a bit easier
`LAW OF SINES:`
\[\frac{ \sin(A) }{ a }=\frac{ \sin(B) }{ b }\]

Plug in what we know
\[\frac{ \sin(90) }{ 20 }=\frac{ \sin(A) }{ 5 }\]
\[A=\sin^{-1} (\frac{ 5\sin(90) }{ 20 })\]

Answer 5

Technically, the law applies to the whole triangle so it should be
\[\frac{ \sin(A) }{ a }=\frac{ \sin(B) }{ b }=\frac{ \sin(C) }{ c }\]
But you get the idea

Answer 6

Your answer is correct though.

Answer 7

Eh, it doesn't make it simpler. But later on you'll see that it's great to have.

Answer 8

Yes, it can be useful, but maybe not in this particular case

Answer 9

Thanks!