Drupal 7. Taxonomy. Term name override

I have vocabulary Angle, with terms: 10, 15, 20 etc. I want to have taxonomy page h1 title "Angle $term_name mm" - Angle 10mm, Angle 15mm.. Please push me on the right way or just help.

If you are not using modules like Panels or Views to show taxonomy terms, you may implement hook_preprocess_taxonomy_term() in your theme:

function mytheme_preprocess_taxonomy_term(&$variables) {
  $term = $variables['term'];
  // Alter only terms of Angle vocabulary.
  if ($term->vocabulary_machine_name == 'angle') {
    // Alter only taxonomy term pages, not listings.
    if ($variables['page']) {
      $name = t('Angle @name mm', array('@name' => $term->name));
      drupal_set_title($name);
    }
  }
}

P.S. Why not using correct term names from the start? If you need raw angle values (10, 15 etc.) you may add corresponding numeric field to your vocabulary.