Code XAML

<Grid>
        <Border x:Name="MainBorder" Height="86" Width="390" HorizontalAlignment="Center" VerticalAlignment="Center" BorderThickness="1.5" BorderBrush="Gray" CornerRadius="10">
            <Grid>
                <Button x:Name="TogButton" HorizontalAlignment="Right" Margin="5" Style="{StaticResource MaterialDesignFlatButton}" Click="Button_Click">
                    <materialDesign:PackIcon Kind="ChevronDown" Width="24" Height="24">
                        <materialDesign:PackIcon.RenderTransform>
                            <RotateTransform x:Name="iconRotation" CenterX="12" CenterY="12"/>
                        </materialDesign:PackIcon.RenderTransform>
                    </materialDesign:PackIcon>
                </Button>
                <TextBlock Name="tb1" Text="Why shouldn't we trust atoms?" HorizontalAlignment="Left" VerticalAlignment="Center" FontWeight="Medium" FontSize="17" Margin="10"/>
                <TextBlock Name="tb2" Grid.Row="1" Text="They make up everything" HorizontalAlignment="Left" VerticalAlignment="Center" FontWeight="Regular" FontSize="14" Margin="10 100 0 0"/>
            </Grid>
        </Border>
    </Grid>

Code Behind

 public bool IsOpen { get; set; }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            if (IsOpen)
            {
                DoubleAnimation doubleAnimation = new DoubleAnimation(86, new Duration(TimeSpan.FromMilliseconds(300)));
                doubleAnimation.EasingFunction = new PowerEase();
                MainBorder.BeginAnimation(HeightProperty, doubleAnimation);



                ThicknessAnimation thicknessAnimation = new ThicknessAnimation(new Thickness(10), new Duration(TimeSpan.FromMilliseconds(300)));
                thicknessAnimation.EasingFunction = new PowerEase();
                TogButton.BeginAnimation(MarginProperty, thicknessAnimation);

                ThicknessAnimation thicknessAnimationtb1 = new ThicknessAnimation(new Thickness(10), new Duration(TimeSpan.FromMilliseconds(300)));
                thicknessAnimationtb1.EasingFunction = new PowerEase();
                tb1.BeginAnimation(MarginProperty, thicknessAnimationtb1);

                ThicknessAnimation thicknessAnimationtb2 = new ThicknessAnimation(new Thickness(10, 100, 0, 0), new Duration(TimeSpan.FromMilliseconds(300)));
                thicknessAnimationtb2.EasingFunction = new PowerEase();
                tb2.BeginAnimation(MarginProperty, thicknessAnimationtb2);

                DoubleAnimation rotationLeftIconMenunAnimation = new DoubleAnimation(0, TimeSpan.FromMilliseconds(300));
                rotationLeftIconMenunAnimation.EasingFunction = new PowerEase();
                iconRotation.BeginAnimation(RotateTransform.AngleProperty, rotationLeftIconMenunAnimation);
                IsOpen = false;
            }
            else
            {
                DoubleAnimation doubleAnimation = new DoubleAnimation(120, new Duration(TimeSpan.FromMilliseconds(300)));
                doubleAnimation.EasingFunction = new PowerEase();
                MainBorder.BeginAnimation(HeightProperty, doubleAnimation);



                ThicknessAnimation thicknessAnimation = new ThicknessAnimation(new Thickness(5, 5, 5, 70), new Duration(TimeSpan.FromMilliseconds(300)));
                thicknessAnimation.EasingFunction = new PowerEase();
                TogButton.BeginAnimation(MarginProperty, thicknessAnimation);

                ThicknessAnimation thicknessAnimationtb1 = new ThicknessAnimation(new Thickness(10, 10, 0, 70), new Duration(TimeSpan.FromMilliseconds(300)));
                thicknessAnimationtb1.EasingFunction = new PowerEase();
                tb1.BeginAnimation(MarginProperty, thicknessAnimationtb1);

                ThicknessAnimation thicknessAnimationtb2 = new ThicknessAnimation(new Thickness(10, 20, 0, 0), new Duration(TimeSpan.FromMilliseconds(300)));
                thicknessAnimationtb2.EasingFunction = new PowerEase();
                tb2.BeginAnimation(MarginProperty, thicknessAnimationtb2);

                DoubleAnimation rotationLeftIconMenunAnimation = new DoubleAnimation(180, TimeSpan.FromMilliseconds(300));
                rotationLeftIconMenunAnimation.EasingFunction = new PowerEase();
                iconRotation.BeginAnimation(RotateTransform.AngleProperty, rotationLeftIconMenunAnimation);
                IsOpen = true;
            }           
        }