an class="op">*</span><span class="va">x</span><span class="op">)</span><span class="op">)</span></span>
<span><span class="va">Z</span><span class="op">$</span><span class="va">x</span> <span class="op">&lt;-</span> <span class="va">Z</span><span class="op">$</span><span class="va">x</span><span class="op">*</span><span class="fl">180</span><span class="op">/</span><span class="va">pi</span></span>
<span><span class="va">Z</span><span class="op">$</span><span class="va">y</span> <span class="op">&lt;-</spa