activity_polygon_button.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:id="@+id/backgroundLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".PolygonButtonActivity">

    <!-- if you do not like basin effect -> remove below polygonView and use only polygonButton -->
    <com.github.sshadkany.shapes.PolygonView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:shape_polygon_shadow_type="drop_shadow"
        app:shape_polygon_side="4">

        <com.github.sshadkany.PolygonButton
            android:id="@+id/polygon_button"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            app:shape_polygon_side="4">


            <ImageView
                android:id="@+id/imageView3"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_gravity="center"
                android:padding="60dp"
                android:tint="#000000"
                app:srcCompat="@drawable/abc_vector_test" />
        </com.github.sshadkany.PolygonButton>

    </com.github.sshadkany.shapes.PolygonView>


</androidx.constraintlayout.widget.ConstraintLayout>