activity_formulario.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.rodrigo.agenda.FormularioActivity"
    tools:layout_editor_absoluteY="81dp"
    tools:layout_editor_absoluteX="0dp">

    <EditText
        android:id="@+id/nome"
        android:layout_width="368dp"
        android:layout_height="wrap_content"
        android:hint="Nome"
        android:inputType="textCapCharacters"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toTopOf="@+id/endereco"
        android:layout_marginLeft="8dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginTop="8dp"
        android:layout_marginRight="8dp"
        app:layout_constraintVertical_bias="0.505"
        app:layout_constraintRight_toRightOf="parent" />

    <EditText
        android:id="@+id/endereco"
        android:layout_width="368dp"
        android:layout_height="wrap_content"
        android:hint="Endereço"
        tools:layout_editor_absoluteX="8dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toTopOf="@+id/telefone" />

    <EditText
        android:id="@+id/telefone"
        android:layout_width="368dp"
        android:layout_height="wrap_content"
        android:hint="Telefone"
        android:inputType="phone"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toTopOf="@+id/site"
        android:layout_marginRight="8dp"
        app:layout_constraintRight_toRightOf="parent" />

    <EditText
        android:id="@+id/site"
        android:layout_width="368dp"
        android:layout_height="wrap_content"
        android:hint="Site"
        android:inputType="textUri"
        tools:layout_editor_absoluteY="356dp"
        android:layout_marginRight="8dp"
        app:layout_constraintRight_toRightOf="parent"
        android:layout_marginLeft="8dp"
        app:layout_constraintLeft_toLeftOf="parent" />
    <RatingBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:numStars="5"
        android:max="10"
        android:id="@+id/ratingBar"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="8dp"
        android:layout_marginRight="8dp"
        app:layout_constraintRight_toRightOf="parent"
        android:layout_marginLeft="8dp"
        app:layout_constraintLeft_toLeftOf="parent" />

</android.support.constraint.ConstraintLayout>