Set border for TriangleView

[alirezaeiii]

I am using triangleView :

          <com.github.florent37.shapeofview.shapes.TriangleView
            android:id="@+id/triangle"
            android:layout_width="30dp"
            android:layout_height="13dp"
            android:layout_above="@+id/tab_layout"
            android:rotation="180">

            <View
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@color/colorPrimary" />

        </com.github.florent37.shapeofview.shapes.TriangleView>

        <com.sample.android.contact.widget.ListenableTabLayout
            android:id="@+id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="48dp"
            android:layout_alignParentBottom="true"
            android:background="@color/colorPrimary"
            app:tabIndicatorHeight="2dp"
            app:tabSelectedTextColor="@color/colorAccent"
            app:tabTextColor="@android:color/white" />

I want to create border for my TriangleView as well as top of my ListenableTabLayout with grey color. How can I make it?