tolong jawab no 4,5,6&7 thx

4) 180= <ABC + pelurus <ABC
180 = <ABC + 100
<ABC = 80

180 = <BCA + pelurus <BCA
180 = <BCA + 145
<BCA = 35

<ABC + <BCA + <CAB = 180
80 + 35 + <CAB = 180
115 + <CAB = 180
<CAB = 65

jadi, besar sudut A = besar sudut CAB = 65°

5) <ABC + <BCA + <CAB = 180
(4x - 15) + (x + 5) + 60 = 180
5x + 50 = 180
5x = 130
x = 26

besar <ABC = 4x - 15 = 4(26) - 15 = 89

jadi, besar <ABC adalah 89°

6) 125 + a = 180 (sudut sehadap)
a = 55

jadi, nilai y =?. mungkin maksudnya nilai a = 55°

7) <ABD + <BDC = 90
(2x + 20) + (3x - 10) =90
5x + 10 = 90
5x = 80
x = 16

besar sudut BDC = 3x - 10 = 3(16) - 10 = 48 - 10 = 38

jadi, besar sudut BDC adalah 38°