Posted by Shelby on .
Find angle A if angle A is supplementary to angle B, angle B is supplementary to angle C, angle B equals 12x plus 8, and angle C equals 8x minus 8

geometry 
Reiny,
so clearly
A+B = 180
B+C = 180
subtract them
A  C = 0
A = C
given: B = 12x+8 , C = 8x  8
in B+C=180
12x+8 + 8x8 = 180
20x = 180
x = 9
so C = 728 = 64
but A = C
so A = 64
check:
A = 64°
B = 116°
C = 64°
is A+ B = 64+116 = 180 ? YES
is B+C = 116+64 = 180° yes
is A = C ? yes