perhatikan gambar berikut

4.
p = 180-63.
p = 117. C.

5.
(x+50) + (x-30) = 180.
2x+20= 180.
2x = 180-20.
2x = 160.
x = 160/2.
x = 80. B.

6.
A² + B¹ = 180.
54 + 4y = 180.
4y = 180-54.
4y = 126/4.
y = 126/4.
y = 31,5.

A³ + A² = 180.
3x + 54 = 180.
3x = 180-54.
3x = 126.
x = 126/3.
x = 42.

jadi.
x + y = 42 + 31,5.
x + y = 73,5. D.

sudut A3 Dan B1 sama besar.
jadi x+y=42+31,5
=73,5