Answer:
m∡A = 41.4°
m∡B = 48.6°
m∡C = 90°
a = 3
b = 9
c = 12
Step-by-step explanation:
to find the length of side 'a' I used the Pythagorean Theorem to get:
a² + 9² = 12²
a² + 81 = 144
a² = 63
a =
which equals 
which is 3
to find m∡B I found the arcsin(B) = 9/12 to get 48.6
to find m∡A I subtracted the sum of 90 + 48.6 from 180°
Answer:
1215 minutes are the possible numbers he has used his phone in a month.
Step-by-step explanation:
He has a monthly fee of 14$ then to the least that he has been charged we need to substract the monthly fee as follows:
Monthly charged = 74,75-14
Monthly charged= 60,75$
Then he pays an additional 0,05 $/minute of use, to know the consume:
Minutes= 
Minutes= 1215 possible numbers of minutes he has used his phone.