RelativeLayout

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:layout_marginTop="10dp"
    android:layout_marginLeft="5dp"
    android:layout_marginRight="5dp"
    tools:context="com.example.reaz.relativelayout.MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button 1"
        android:id="@+id/buone"
        />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/butwo"
        android:layout_below="@+id/buone"
        android:text="butwo"

        />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button 3"
        android:layout_toRightOf="@id/butwo"
        android:layout_below="@id/buone"

        />

</RelativeLayout>