Castillo, Aida C. <br/><br/>Modules in plane Trigonometry. Castillo, Aida c.  -- Quezon city.  Great Books Trading,  2003 <br/>130 p. :  ill. ;  22 cm <br/><br/> Include Bibliographical references. <br/><br/><label>ISBN: </label>971-8581-56-1 <br/><br/><label>Subjects--Topical Terms: </label><br/>Plane trigonometry-- study and teaching (higher)<br/>Plane trigonometry-- Problems, exercises, ets.