title: Unable to get exact circle shape when using card view
body: <p>I'm using card view for floating action button in android material design. I'm using following code for get the circle </p>
  
  <pre><code>&lt;android.support.v7.widget.CardView
      android:id="@+id/fab"
      android:layout_width="38dp"
      android:layout_height="38dp"
      android:layout_marginBottom="10dp"
      android:layout_marginRight="10dp"
      card_view:background="@color/blue"
      card_view:cardCornerRadius="19dp"
      card_view:cardPreventCornerOverlap = "false"
      card_view:cardElevation="6dp" &gt;
  &lt;/android.support.v7.widget.CardView&gt;
  </code></pre>
  
  <p>I have set corner radius as half of width. but still I can't get the circle shape.<img src="https://i.stack.imgur.com/ZQzEX.jpg" alt="enter image description here"></p>