# What am I doing wrong?

• Jan 31st 2010, 08:03 AM
iluvmathbutitshard
What am I doing wrong?
Use the given information to solve the triangle:
C = 85˚20', a = 35, c = 50
So I have to find A, B, and b

My work:
(sin 85 1/3) / (50) = (Sin A) / (35)
0.0199 = (Sin A) / (35)
A = 0.697

But this doesn't make sense. Shouldn't the amount be higher?

Any help is appreciated.
• Jan 31st 2010, 08:11 AM
lovemath
C = 85˚20', a = 35, c = 50
Have:
$\displaystyle \frac{sinC}{c}=\frac{sinA}{a}$
So: $\displaystyle sinA=\frac{sinC . a}{c}=0.698$
--> $\displaystyle A = 44^014'$
--> $\displaystyle B=50^026'$ --> b ...
• Jan 31st 2010, 08:22 AM
HallsofIvy
Quote:

Originally Posted by iluvmathbutitshard
Use the given information to solve the triangle:
C = 85˚20', a = 35, c = 50
So I have to find A, B, and b

My work:
(sin 85 1/3) / (50) = (Sin A) / (35)
0.0199 = (Sin A) / (35)
A = 0.697

But this doesn't make sense. Shouldn't the amount be higher?

Any help is appreciated.

Well, I would have rounded that to 0.698 but it really doesn't make and difference. It certainly makes sense to me. Why do you think it should be higher? It can't be much higher. It has to be less than 1 certainly. And, since a= 35< 50= c, A must be less than C and so sin A< sin C. With sin A= .697, A is about 44 degrees and 17 minutes. Nothing wrong with that.