Question

Please help me with these problems; geometry is really getting on my nerves. T-T

Answer 1

For #19 part A :

By vertical angles and then same side interior angles 3x + 2x = 180
5x = 180
x = 36

For #19 part B:

You are correct with the 35, but you missed the fact that the 105 angle is supplementary with the unknown angle inside the triangle. So:

180 - 105 = 75

Then:

180 = 35 + 75 + x
180 = 110 + x
x = 70

Last question:

Do you know what the symbol means? Text me and tell me and I can answer it for you. :)

Answer 2

Veridian has great answers. I'm only posting this as a supplement to help provide the diagrams showing the various angles, that lead into the equations Veridian uses.