Answer:
The other angle is 190-7x.
Step-by-step explanation:
Angles in a triangle add up to 180 degrees.
Let A be the third angle.
A + (3x-20) + (4x+10) = 180
A = 180 - (3x - 20) - (4x + 10) = 190 - 7x
180-96= 84
That means 8x+12=84
84-12=72
That means 8x=72
72÷8=9
therefore X=9
The first figure has 3 line segments.
the second figure has 3+3 =3*2 = 6 line segments
the third figure has 3+3+3 = 3*3 = 9 line segments
the fourth figure has 3+3+3+3=3*4=12 line segments...
so it is clear that:
the 20th figure has 3*20=60 line segments.
Answer: 60
