When teaching diatonic triads to my music theory students, one of their first tasks is to write the diatonic triads in all keys. This sheet contains the answers for all 15 major scales. Roman numerals are written in the contemporary style taught at Berklee College of Music. All Roman numerals are capital with qualities included. This worksheet is meant to be handed out as a resource after the students have finished writing the diatonic triads in all keys.