Question 908628
x + 3(90-x) + (180-x)/7 = 180°
7x + 21(90-x) + (180-x) = 1260
Solve for x
-15x = 1260 - 1890 - 180
x = 54°
3(90-54) = 108°
(180-54)/7 = 18°
and..checking...
54° + 108° + 18° = 180