activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:gravity="center_horizontal"
    android:background="@drawable/bckg"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="in.co.whiznet.nurseryapp.MainActivity">
   <LinearLayout
       android:gravity="right"
       android:layout_margin="10dp"
       android:layout_width="match_parent"
       android:layout_height="40dp">
       <ImageView
           android:id="@+id/volume"
           android:onClick="volume"
           app:srcCompat="@drawable/ic_volume_up_black_24dp"
           android:layout_width="40dp"
           android:layout_height="40dp" />
   </LinearLayout>


    <ImageView
        android:id="@+id/image"
        android:background="@color/optionsimagebackgroundcolor"
        android:src="@drawable/ic_abc"
        android:onClick="next"
        android:layout_marginBottom="50dp"
        android:padding="16dp"
        android:layout_width="130dp"
        android:layout_height="130dp" />

    <ImageView
        android:id="@+id/image2"
        android:padding="16dp"
        android:background="@color/optionsimagebackgroundcolor"
        android:layout_width="130dp"
        android:layout_height="120dp"
        android:onClick="next"
        android:layout_marginBottom="150dp"
        android:src="@drawable/ic_assignment_black_24dp" />
    <ImageView
        android:id="@+id/about"
        android:src="@drawable/abt"
        android:onClick="next"
        android:layout_gravity="right"
        android:layout_width="60dp"
        android:layout_height="60dp" />


</LinearLayout>