# Find Remaining Angles and Sides

• March 27th 2013, 02:18 PM
ktrousdale
Find Remaining Angles and Sides
Find remaining angles and side if they exist. If no triangle exists, say "No triangle"

a=4 a=1 y=100 degrees

(the problem does not state where angle y lies) please solve and explain process I am doing a similar problem but found this one in the book.
• March 27th 2013, 03:13 PM
Shakarri
Re: Find Remaining Angles and Sides
What is a?
• March 27th 2013, 03:28 PM
Prove It
Re: Find Remaining Angles and Sides
Quote:

Originally Posted by Shakarri
What is a?

I love your signature btw Shakarri :D
• March 28th 2013, 04:39 AM
ktrousdale
Re: Find Remaining Angles and Sides
Quote:

Originally Posted by Shakarri
What is a?

Oh that was totally my fault it is a=4 b=1 and y=100 degrees
• March 28th 2013, 06:27 AM
HallsofIvy
Re: Find Remaining Angles and Sides
If y is the angle between sides a and b then you can find the third side by using the "cosine law":
$c^2= 4^2+ 1^2- 2(4)(1)cos(100)$

You can then find the angle opposite, say, a, using the "sine law":
$\frac{sin(a)}{4}= \frac{sin(100)}{c}$.

If angle y is NOT between the two sides, then there is no such triangle.