Can I use full frame pentax k lenses on aps c?

Here is what the site says about that.

From Pentax K-S1: Pentax K-S1: A DSLR by Pentax with a 20.1-megapixel APS-C sensor, announced in 2014.

From Pentax K-3: Pentax K-3: A DSLR by Pentax with a 24.4-megapixel APS-C sensor, announced in 2013.

Quoted from this site's pages.