tolong bantu jawab... besok pengen dikumpulin!!

jawab
segi empat talibusur

a.  <B + <D = 180
5x+ 4x = 180
9x = 180
x = 20

b.<B = 5x = 5(20)= 100

c. <A + <B = 180
2y + y + 18 = 180
3y = 180- 18
3y = 162
y = 54

d. <C = y + 18  = 54+ 18 = 72