), then your thumb points down in the direction (0,0,-3). If you repeat this with your left hand instead of right hand, then your thumb points up.</p>

  <div class="problem">
    <ul>
      <li>Use determinants to find the area of the triangle with
      vertices $(0,0)$, $(-2,5)$, and $(3,4)$.</li>

      <li>What would you change if you wanted to find the area of
      the triangle with vertices $(-3,1)$, $(-2,5)$, and $(3,4)$?
      Find this area.</li>
    </ul>
  </div>
</section></section>
<section> 