the interior angles of a triangle add up to 180 degrees
a = 1st angle, b = 2nd angle, c = 3rd angle
c = 6a
b = a + 60
a + b + c = 180
a + (a + 60) + (6a) = 180
8a + 60 = 180
8a = 180 - 60
8a = 120
a = 120/8
a = 15 <=== here is one angle
b = a + 60
b = 15 + 60
b = 75 <=== and another one
c = 6a
c = 6(15)
c = 90 <=== and the last angle
