Answer:
a.
2x+4x+3x=180 sum of interior angle of the triangle is 180
9x=180
x=180/9=20
b.
x-20+x+10+x-20=180sum of interior angle of the triangle is 180
3x-30=180
3x=180+30
x=210/3=70
c.x+10+x+20+x=180 linear pair
3x+30=180
3x=180-30
x=150/3=50
A: x=20
Step-by-step explanation:
angles in a triangle always equal 180° so knowing this 2x+3x+4x=180
9x÷9=x
180÷9=20
