n>(<span class="dv">0</span>, <span class="dv">0</span>)) +<span class="st"> </span><span class="kw">scale_x_continuous</span>(<span class="st">"Internal angle /degrees"</span>, <span class="dt">expand =</span> <span class="kw">c</span>(<span class="dv">0</span>, 
    <span class="dv">0</span>), <span class="dt">breaks =</span> <span class="kw">seq</span>(<span class="dv">0</span>, <span class="dv">90</span>, <span class="dt">by =</span> <span class="dv">15</span>))

<span class="kw">grid.arrange</span>(p1,