Answer:
10 degrees = C
Step-by-step explanation:
Total internal angles add to 180 degrees.
Add all values of c and set equal to 180.
18c = 180.
c=10
c = 10
3c + 6c + 9c = 180 degrees. Every triangle has 180 degrees.
18c = 180 Combine the like terms. Divide by 18
18c/18 = 180/18
