275

$A=\frac{1}{2}ab\sin\gamma$
$11=\frac{1}{2}\cdot5\cdot8{,}8\sin\gamma$
$11=22\sin\gamma\ \parallel:22$
$0{,}5=\sin\gamma\$
$\gamma=30°\ tai\ 180°-30°=150°$
$c^2=a^2+b^2-2ab\cos\gamma$
$c^2=26.229...cm\ tai\ 178.650...cm\ \parallel\sqrt{ }$

$c=\pm5{,}121...\ \approx\pm5{,}1cm\ tai\ \pm13.366...\approx\pm13{,}4cm$

hylätään negatiiviset tulokset

$c=5{,}1cm\ tai\ 13{,}4cm$