form api textarea drupal 8 code example

Example: textarea in custom form drupal 7

$form['life_story'] = array(
  '#title' => t('Your Life Story'),
  '#type' => 'textarea',
  '#description' => 'Tell me all about your life',
  '#default_value' => 'First I was born, and then ...',
  '#rows' => 10,
  '#cols' => 60,
  '#resizable' => TRUE,
);