What do we call a sharp, flat, or natural sign that raises or lowers a note in a measure?

a. key signature

b. staff

c. accidental

d. accent mark

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

To prove that angle def = angle dgf by sas, what additional information is needed? def congruent to dgf dfe congruent to dfg de congruent to dg dg congruent to gf