
This result is actually true for any exterior angle. The exterior angle of a triangle is equal to the sum of the two remote angles, and above is a short proof of it.
Answer:
Division. The niece can divide both sides of the equation by 19 to find the answer.
Let me know if this helps!
3! =3 x 2 x 1 = 6
Y!= Y x (y-1) x ... x 1=
If you start and the begging of the year and the end and how much you make and at the end of the year you will know our income.