tentukan hasil dari x° + y° + z°

a. 40 + 7x = 180
            7x = 140
              x = 20
b. 80 + 2y + 40 = 180
                    2y = 60
                      y = 30
c. 4z = 180 - 2y - 40
    4z = 180-60-40
    4z = 80
      z = 20

x+y+z = 20+30+20 = 70

7x° + 40°=180° (sudut berpelurus)
7x°=180° - 40°.
7x°=140°.
x°=140° : 7.
x°=20°.
80° + 2y°=7x° (sudut dalam berseberangan)
80° + 2y°=140°.
2y°=140° - 80°.
2y°=60°.
y°=60° : 2.
y°=30°.
40° + 2y° + 4z°=180°.
40° + 60° + 4z°=180°.
4z°=180° - (40° + 60°)
4z°=180° - 100°.
4z°=80°.
z°=80° : 4.
z°=20°.
x° + y° + z°=20° + 30° + 20°=70°.