Answer:
C= -5
D = 7
Step-by-step explanation:

Answer:
Step-by-step explanation:
The sum of the interior angles of a polygon with n side is

So, for a polygon with 5 sides the expression is

Answer:
13:3
Step-by-step explanation:
A=x B=y
first; x= 360+y
later;x= 216+y
A:B
216+y: 1/2y = 6: 1
216+y/y÷2 =6/1
216+y = 3y
y = 108
first; x =360+y
360 +108
468
A:B = 468:108
13:3