Geometry question. Supplementary angles.?

Question

Angle C and angle D are supplementary. The measure of angle D is eight times the measure of angle C. Find the measurement of angle C and angle D.

Answer 1

ok so since c and d are supplementary, they equal 180

and since d equals 8 times c, u can replace that in the equation so it would become

(8*c)+c=180

then u add 8c plus the c and they still equal 180

9c=180

then u have to get c all alone, so u divide 180 by 9 to get rid of the 9 on the left side

180/9=c

c=20

d=8*c

d=160

c=20, d=160

Answer 2

20

explanation

d + c = 180

(8c) + c = 180

9c = 180

c = 20