You should try nested Linear layout and thus using weights you may achieve a flexible user interface, try this
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
android:orientation="vertical"
tools:context=".MainActivity" >
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="60dip" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/textView3"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="#808080" />
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical" >
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<Button
android:id="@+id/button2"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<Button
android:id="@+id/button3"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<TextView
android:id="@+id/textView5"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
</LinearLayout>
<TextView
android:id="@+id/textView2"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="#808080" />
</LinearLayout>