android - Design a round button over two colored layouts -

i'm trying design :

currently i'm having issue putting button @ "the middle" of 2 layouts reunion point. there way ?

thanks.

here way it

<?xml version="1.0" encoding="utf-8"?>  <relativelayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1">   <linearlayout     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical"     android:weightsum="1">       <linearlayout         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_weight="0.5"         android:background="#ff0000">          <!-- add content here -->      </linearlayout>       <linearlayout         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_weight="0.5"         android:background="#ffff00"         android:weightsum="0.5">          <!-- add content here -->      </linearlayout>  </linearlayout>  <button     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_centerinparent="true"     android:background="#000000"     android:text="test"     android:textcolor="#ffffff"/>  </relativelayout> 

output:

you can change layout height android:layout_weight="0.5"