tolong bantu ya nomor 30,31

no 30
<k : <l = 4 : 5
<k + <l = 180°
<k = <m
<k = 4/9 . 180 = 80°
<m = 80°
no 31
k = 80
k = 2(p + l)
p + l = 80/2 = 40
p : l = 3 : 5
p = 3/8 . 40 = 15
l = 5/8 . 40 = 25
luas = 25 . 15 = 375