Flip Coin App Main Layout

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.ssaurel.coinflip.MainActivity">

    <ImageView
        android:id="@+id/coin"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:src="@drawable/heads"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="40dp"/>

    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/coin"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="60dp"
        android:text="Flip"/>


</RelativeLayout>