Answer:
11
Step-by-step explanation:
198 ÷ 18 = 11
x = 11
......
x= 22.5
Because the opposite sides are congruent, so are the angles.
4x+20=40
subract 20 from both sides
4x=20
divide by 4 on both sides
x=5
It's 15
17(1)=17
17-2=15
