tolong jawab pake cara yups biar ngerti

Nomor 1
<Δ = 180
90+65+x = 180
155+x = 180
x = 180-155
x = 25
180-25 = 155
155 = 29a+10
155-10 = 29a
145 = 29a
145 : 29 = a
5 = a
Jawaban : d

Nomor 2
<ABC = 180-86
= 94
jawaban : d

Nomor 3
<CDE = 90 + (180-(90+40))
= 90 + (180-130)
= 90 + 40
= 130
jawaban : b

Semoga membantu...